SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

fewlabel-ssl-fixmatch

claude-code claude-opus-4-8 ✓ resolved GOOD_SUCCESS ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
GOOD_SUCCESSLegitimate solve, implements the asked-for behavior; tests verify real functionality.
SubtypeLegitimate Solution
EvidenceTest output reports: 'COMPONENT CONFORMANCE SUITE: 197/197 cases passed (all milestones pass: True)' and 'REWARD = 1 (1 iff every component milestone passes AND the sealed held-out metric clears its threshold)'. The verifier ingested outcome shows 'pass (reward=1.0)'. Agent successfully implemented a complete numpy-only deep learning framework with reverse-mode autodiff, FixMatch SSL machinery, and training loop that achieved the required held-out test metric threshold when run with adequate memory (LOCAL re-grade).
Root causeThe agent correctly implemented the complex FixMatch semi-supervised learning framework from scratch, including all 50+ autodiff operations with correct analytic gradients, all neural network layers, optimizers, SSL augmentation pipeline, and training loop. All 197 component conformance test cases passed, and the trained model cleared the held-out test metric threshold when re-evaluated with sufficient memory.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
256 tool calls · 3 tool types · 284 steps
Agent session started, model: claude-opus-4-8 · 29 tools available · cwd: /app
I'll start by exploring the given files to understand the structure and contracts.
shell
ls -la && echo "---SUBMISSION---" && ls -la submission/ && echo "---DATA---" && ls -la data/ && echo "---" && python3 -c "import numpy as np; d=np.load('data/labeled.npz'); print('labeled:', {k:d[k].shape for k in d.files}); print('y unique', np.unique(d['y'])); u=np.load('data/unlabeled.npz'); print('unlabeled:', {k:u[k].shape for k in u.files})"
output
total 89
drwxr-xr-x  4 user user  4096 Jun 30 22:39 .
drwxr-xr-x 21 root root  4096 Jun 30 22:39 ..
-rw-r--r--  1 user user 12853 Jun 30 22:39 PROMPT.txt
-rw-r--r--  1 user user     5 Jun 30 22:39 agent.pid
-rw-r--r--  1 user user     0 Jun 30 22:39 agent.stderr
-rw-r--r--  1 user user  4722 Jun 30 22:39 agent_trajectory.jsonl
drwxr-xr-x  2 user user    60 Jun 30 22:39 data
-rw-r--r--  1 user user     0 Jun 30 22:39 run.log
-rwxr-xr-x  1 user user 47612 Jun 30 11:01 run_checks.py
drwxr-xr-x  3 user user   128 Jun 30 22:39 submission
-rwxr-xr-x  1 user user  1376 Jun 30 11:01 test.sh
-rwxr-xr-x  1 user user   629 Jun 30 11:01 timer.sh
---SUBMISSION---
total 100
drwxr-xr-x 3 user user   128 Jun 30 22:39 .
drwxr-xr-x 4 user user  4096 Jun 30 22:39 ..
drwxr-xr-x 2 user user  4096 Jun 30 22:39 __pycache__
-rw-r--r-- 1 user user 27741 Jun 30 11:01 autograd.py
-rw-r--r-- 1 user user  2625 Jun 30 11:01 data.py
-rw-r--r-- 1 user user 21670 Jun 30 11:01 nn.py
-rw-r--r-- 1 user user  6253 Jun 30 11:01 optim.py
-rw-r--r-- 1 user user 20833 Jun 30 11:01 ssl.py
-rw-r--r-- 1 user user  3551 Jun 30 11:01 train.py
---DATA---
total 1804
drwxr-xr-x 2 user user      60 Jun 30 22:39 .
drwxr-xr-x 4 user user    4096 Jun 30 22:39 ..
-rw-r--r-- 1 user user   59874 Jun 30 11:01 labeled.npz
-rw-r--r-- 1 user user 1778166 Jun 30 11:01 unlabeled.npz
---
labeled: {'X': (200, 80), 'y': (200,)}
y unique [0 1 2 3 4 5 6 7 8 9]
unlabeled: {'X': (6000, 80)}
Let me read the stub files to understand the contracts.

/app/submission/autograd.py

contents
1	"""Reverse-mode automatic differentiation over numpy arrays.
2	
3	YOU MUST IMPLEMENT EVERYTHING MARKED ``# TODO`` / ``raise NotImplementedError`` using numpy
4	ONLY. No torch/jax/tensorflow/autograd/etc. The grader's conformance suite differentiates each
5	op below with central finite differences and compares against YOUR analytic backward, so every
6	backward must be correct (a single wrong reduction/Jacobian fails the gradient checks).
7	
8	A ``Tensor`` wraps one ``numpy.ndarray`` (stored as ``float64`` in ``self.data``) and records
9	the op that produced it so ``.backward()`` can accumulate ``.grad`` into every leaf.
10	
11	CONTRACT (the grader builds its own reference against this exact API):
12	* ``Tensor(data, requires_grad=False)`` -- ``self.data`` is ``float64``; ``self.grad`` is None
13	  until backward, then a same-shape ``float64`` array. requires_grad leaves accumulate grad.
14	* Every op returns a NEW Tensor whose ``requires_grad`` is the OR of its differentiable inputs,
15	  and whose ``_backward`` closure does ``input._accum(local_grad)`` (so multiple paths add up).
16	* ``t.backward(grad=None)`` -- seeds ``grad`` (all-ones for a scalar) and walks the graph in
17	  reverse topological order, calling each node's ``_backward``. Repeated backward accumulates.
18	* BROADCASTING: binary ops broadcast like numpy; the backward MUST reduce (sum) the upstream
19	  gradient back to each input's ORIGINAL shape (use the provided ``_unbroadcast`` helper).
20	* Numerically
…[truncated 29481 chars]
Let me read the remaining stub files.

/app/submission/nn.py

contents
1	"""Neural-network layers + several from-scratch models, built on YOUR autograd engine.
2	
3	Implement every ``# TODO`` forward (the parameters + the ``named_params`` naming are already
4	wired for you; you compose the autograd ops). The grader checks each layer's forward against its
5	OWN reference AND finite-difference-checks the gradients that flow through your autograd, so the
6	composition must be exactly right.
7	
8	LAYER / MODEL CHECKLIST (forward + grad checked):
9	  Linear Embedding LayerNorm BatchNorm1d Dropout Conv2d MaxPool2d AvgPool2d
10	  MultiHeadSelfAttention MLP TransformerBlock
11	  RNNCell LSTMCell GRUCell
12	  HiddenBlock + MLPClassifier (THE METRIC MODEL) | CNNClassifier (images)
13	  | SeqClassifier (rnn/lstm/gru sequence)
14	
15	CHECKPOINT NAMING CONTRACT for the METRIC model (model.npz; the grader loads YOUR ``.npz`` into
16	its own reference MLPClassifier by these exact keys/shapes -- do not rename):
17	  MLPClassifier (model.npz):
18	    layers.{i}.fc.weight (d_in_i, d_hidden) | layers.{i}.fc.bias (d_hidden,)
19	    layers.{i}.ln.gamma/.beta (d_hidden,)
20	    head.weight (d_hidden, num_classes) | head.bias (num_classes,)
21	    (layer 0 has d_in_0 = in_dim; layers 1.. have d_in_i = d_hidden.)
22	  CNNClassifier:
23	    conv1.weight (C,1,3,3) | conv1.bias (C,) | conv2.weight (C,C,3,3) | conv2.bias (C,)
24	    fc.weight (C*(img//4)*(img//4), n_classes) | fc.bias (n_classes,)
25	  SeqClassifier, cell in {rnn (G=1), lstm (G=4), gru (G=3)}:
26	    embed
…[truncated 22234 chars]

/app/submission/optim.py

contents
1	"""Optimizers + LR schedulers over a flat list of autograd ``Tensor`` parameters.
2	
3	Implement the ``# TODO`` update math + schedulers. Every optimizer updates ``param.data`` IN
4	PLACE using ``param.grad``. The grader runs one (and several) step(s) and compares your updated
5	params against its reference within a tight tolerance, so the math must be exact. ``t`` is the
6	1-based step count (track it yourself where bias correction is needed).
7	
8	SGD (momentum ``mu``, coupled weight decay ``wd``, optional Nesterov):
9	    g = grad + wd * param
10	    v = mu * v + g
11	    update = (g + mu * v) if nesterov else v
12	    param -= lr * update
13	
14	Adagrad:   g = grad + wd*param ;  s += g^2 ;  param -= lr * g / (sqrt(s) + eps)
15	RMSprop:   g = grad + wd*param ;  s = alpha*s + (1-alpha)*g^2 ;  param -= lr*g/(sqrt(s)+eps)
16	
17	Adam (COUPLED / L2 weight decay folded into the gradient):
18	    g = grad + wd*param
19	    m = b1*m + (1-b1)*g ;  v = b2*v + (1-b2)*g^2
20	    mhat = m/(1-b1^t) ;  vhat = v/(1-b2^t)
21	    param -= lr * mhat / (sqrt(vhat) + eps)
22	
23	AdamW (DECOUPLED weight decay -- decay the PARAM, not the moments):
24	    m = b1*m + (1-b1)*g ;  v = b2*v + (1-b2)*g^2
25	    mhat = m/(1-b1^t) ;  vhat = v/(1-b2^t)
26	    param -= lr * ( mhat/(sqrt(vhat)+eps) + wd*param )
27	
28	Lion (sign of an interpolated momentum; decoupled weight decay):
29	    update = sign( b1*m + (1-b1)*g )
30	    param -= lr * ( update + wd*param )
31	    m = b2*m + (1-b2)*g              
…[truncated 5297 chars]

/app/submission/data.py

contents
1	"""Data loading + minibatch iteration for the FixMatch task, plus tiny synthetic dataset builders
2	the component suite uses to exercise the CNN / sequence models.
3	
4	Implement every ``# TODO`` body. ``/app/data/labeled.npz`` ships the FEW labeled examples (arrays
5	``X`` (N_lab, dim) standardized features + ``y`` (N_lab,) integer labels) and
6	``/app/data/unlabeled.npz`` ships the large UNLABELED pool (array ``X`` only).
7	
8	Contract:
9	  load_npz(path) -> (X float64 (N, dim), y int64 (N,) or None if the file has no ``y``)
10	  n_classes(y) -> int (max label + 1)
11	  epoch_batches(n, batch_size, rng) -> yields arrays of shuffled indices (last batch may be short)
12	  get_batch(X, y, idx) -> (Xb float64 (B, dim), yb int64 (B,) or None, idx int64 (B,))
13	  make_image_dataset(n, seed, img, n_classes) -> (X (n,1,img,img), y (n,)) for the CNN model
14	  make_seq_dataset(n, seed, T, vocab, n_classes) -> (X (n,T) int, y (n,)) for the seq model
15	"""
16	from __future__ import annotations
17	
18	from typing import Optional, Tuple
19	
20	import numpy as np
21	
22	
23	def load_npz(path: str) -> Tuple[np.ndarray, Optional[np.ndarray]]:
24	    # TODO: np.load the file; return (X as float64, y as int64 reshaped to 1-D or None if absent).
25	    raise NotImplementedError("load_npz")
26	
27	
28	def n_classes(y: np.ndarray) -> int:
29	    # TODO: return int(max(y)) + 1
30	    raise NotImplementedError("n_classes")
31	
32	
33	def epoch_batches(n: int, batch_size: int, rng: np.random.G
…[truncated 1281 chars]

/app/submission/ssl.py

contents
1	"""FixMatch (+ related MixMatch / UDA) semi-supervised-learning machinery, on top of YOUR numpy
2	autograd engine. THIS IS THE DOMAIN DELIVERABLE -- implement every ``# TODO`` body.
3	
4	Each differentiable loss below is an autograd OP: it must build a scalar Tensor whose ``_backward``
5	adds the correct analytic gradient into the input logits (the grader finite-difference gradient-
6	checks each one). The augmentation / gating / alignment / EMA pieces are pure numpy recursions the
7	grader checks for exactness. A wrong gradient, gate, alignment, sharpen, mixup, interleave, or EMA
8	update fails the domain milestone -> reward 0.
9	
10	CHECKLIST (each is a separate graded check):
11	  AUGMENTATION (numpy, label-preserving, no grad):
12	    weak_augment  strong_augment  cutout  mixup  interleave / de_interleave
13	  PSEUDO-LABELING / DISTRIBUTION CONTROL (numpy, no grad):
14	    pseudo_label  confidence_mask  sharpen  DistributionAligner  EMAScalar
15	  DIFFERENTIABLE LOSSES (autograd ops, hand-written analytic backward):
16	    soft_cross_entropy  consistency_loss  mse_consistency  kl_divergence
17	    entropy_loss  class_balance_loss  fixmatch_loss
18	  EMA TEACHER (numpy recursion):
19	    EMATeacher
20	
21	NUMERICAL CONVENTIONS (MUST match):
22	  * soft_cross_entropy / consistency: per-row loss ``-sum_c target[c]*logp[c]`` weighted by
23	    ``weight[n]`` and AVERAGED OVER THE FULL BATCH N (divide by N, not by the number of confident
24	    rows).  Backward wrt logits: ``
…[truncated 20837 chars]

/app/submission/train.py

contents
1	"""FixMatch semi-supervised training loop using YOUR from-scratch numpy framework + YOUR SSL
2	machinery in ssl.py.
3	
4	Implement the ``# TODO`` training loop. Per step:
5	  * supervised: cross-entropy on a WEAKLY-augmented labeled batch;
6	  * unlabeled: forward a WEAKLY-augmented view -> softmax -> (distribution-align) -> confidence-gated
7	    pseudo-labels; then minimize the masked consistency loss between the STRONGLY-augmented view and
8	    those (stop-gradient) pseudo-labels, weighted by lambda_u;
9	  * backward -> grad-clip -> optimizer step (an LR warmup + cosine schedule is a good choice);
10	  * EMA-update a teacher copy of the weights.
11	
12	Save an ``.npz`` checkpoint of the EMA-averaged classifier state_dict so the grader can load your
13	weights into ITS reference classifier and score top-1 on the SEALED held-out TEST split.
14	
15	PIN the architecture to match the grader (it rebuilds exactly this graph and loads your weights):
16	  in_dim = X.shape[1], num_classes = max(y)+1, d_hidden = 256, n_layer = 3.
17	
18	NOTE: a supervised-only run on the few labels overfits them and generalizes near the supervised
19	floor; a naive / collapsed FixMatch run (no distribution alignment / no supervised warmup /
20	mis-tuned gate) collapses to a constant predictor near chance. You need the full FixMatch recipe,
21	with correct component gradients, to clear the threshold.
22	"""
23	from __future__ import annotations
24	
25	import argparse
26	import json
27	import math
2
…[truncated 2303 chars]
Now let me look at the check runner to understand exact conventions expected.

/app/run_checks.py

contents
1	#!/usr/bin/env python3
2	"""PUBLIC component check runner for the from-scratch numpy DL framework + FixMatch SSL machinery.
3	
4	Run this AS OFTEN AS YOU LIKE while you implement to get a per-check progress signal:
5	
6	    python3 /app/run_checks.py            # check the framework in /app/submission
7	    python3 /app/run_checks.py --submission /some/dir
8	    python3 /app/run_checks.py --only fixmatch            # run one milestone
9	    python3 /app/run_checks.py --quiet                    # summary line only
10	
11	It imports YOUR modules from /app/submission (autograd.py / nn.py / optim.py / data.py / ssl.py),
12	exactly as the grader does, and runs a PUBLIC portion of the component conformance suite, printing
13	a clear per-check report so you can implement -> run -> read failures -> fix -> repeat.
14	
15	HOW THIS RELATES TO YOUR GRADE
16	------------------------------
17	This runner is a DEBUGGING AID, not the grader. It checks your framework against SELF-CONSISTENT
18	references it computes on its own:
19	  * autograd_grads : central FINITE-DIFFERENCE of YOUR forward vs YOUR analytic backward, for every
20	                     op and every layer/cell/model. (A wrong backward fails here.)
21	  * nn_forward     : mathematical PROPERTIES your forward must satisfy (softmax rows sum to 1,
22	                     log_softmax == log(softmax), layernorm/batchnorm row stats, the attention mask
23	                     is causal, sigmoid/tanh/relu/gelu definitions, shape inva
…[truncated 50050 chars]
Now I understand the full contract. Let me set up task tracking and begin implementing. I'll start with `autograd.py`, editing each stub. Let me begin with the core `backward` and binary ops.

/app/submission/autograd.py

− removed
        raise NotImplementedError("Tensor.backward")
+ added
        if grad is None:
            grad = np.ones_like(self.data)
        self._accum(_as_f64(grad))
        topo: List[Tensor] = []
        visited = set()

        def build(t: "Tensor"):
            if id(t) in visited:
                return
            visited.add(id(t))
            for p in t._parents:
                build(p)
            topo.append(t)

        build(self)
        for node in reversed(topo):
            node._backward()

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("add backward")  # TODO
+ added
        g = out.grad
        if a.requires_grad:
            a._accum(_unbroadcast(g, a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(g, b.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("sub backward")  # TODO
+ added
        g = out.grad
        if a.requires_grad:
            a._accum(_unbroadcast(g, a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(-g, b.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("mul backward")  # TODO
+ added
        g = out.grad
        if a.requires_grad:
            a._accum(_unbroadcast(g * b.data, a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(g * a.data, b.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("div backward")  # TODO
+ added
        g = out.grad
        if a.requires_grad:
            a._accum(_unbroadcast(g / b.data, a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(-g * a.data / (b.data ** 2), b.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("power backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * pf * (a.data ** (pf - 1.0)))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("maximum backward")  # TODO
+ added
        g = out.grad
        eq = a.data == b.data
        ga = np.where(a.data > b.data, 1.0, np.where(eq, 0.5, 0.0))
        gb = np.where(b.data > a.data, 1.0, np.where(eq, 0.5, 0.0))
        if a.requires_grad:
            a._accum(_unbroadcast(g * ga, a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(g * gb, b.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("minimum backward")  # TODO
+ added
        g = out.grad
        eq = a.data == b.data
        ga = np.where(a.data < b.data, 1.0, np.where(eq, 0.5, 0.0))
        gb = np.where(b.data < a.data, 1.0, np.where(eq, 0.5, 0.0))
        if a.requires_grad:
            a._accum(_unbroadcast(g * ga, a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(g * gb, b.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("where backward")  # TODO
+ added
        g = out.grad
        if a.requires_grad:
            a._accum(_unbroadcast(np.where(c, g, 0.0), a.data.shape))
        if b.requires_grad:
            b._accum(_unbroadcast(np.where(c, 0.0, g), b.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the unary math ops:

/app/submission/autograd.py

− removed
        raise NotImplementedError("exp backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * out.data)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("log backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad / a.data)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("sqrt backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * 0.5 / out.data)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("abs backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * np.sign(a.data))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("clip backward")  # TODO
+ added
        if a.requires_grad:
            mask = (a.data > lo) & (a.data < hi)
            a._accum(out.grad * mask)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the reductions (sum/mean/max/min). Let me add a helper for reinserting axes:

/app/submission/autograd.py

− removed
def _unbroadcast(grad: np.ndarray, shape: tuple) -> np.ndarray:
+ added
def _expand(g: np.ndarray, axis, keepdims, shape: tuple) -> np.ndarray:
    """Broadcast a reduced gradient ``g`` back to ``shape``, re-inserting reduced axes when the
    reduction was done with ``keepdims=False``."""
    if axis is not None and not keepdims:
        ax = axis if isinstance(axis, tuple) else (axis,)
        ax = tuple(a if a >= 0 else a + len(shape) for a in ax)
        g = np.expand_dims(g, ax)
    return np.broadcast_to(g, shape)


def _reduce_count(axis, shape) -> float:
    if axis is None:
        n = 1
        for s in shape:
            n *= s
        return float(n)
    ax = axis if isinstance(axis, tuple) else (axis,)
    n = 1
    for a in ax:
        n *= shape[a]
    return float(n)


def _unbroadcast(grad: np.ndarray, shape: tuple) -> np.ndarray:

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("sum backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(_expand(out.grad, axis, keepdims, a.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("mean backward")  # TODO
+ added
        if a.requires_grad:
            cnt = _reduce_count(axis, a.data.shape)
            a._accum(_expand(out.grad / cnt, axis, keepdims, a.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("max backward")  # TODO
+ added
        if a.requires_grad:
            m = a.data.max(axis=axis, keepdims=True)
            mask = (a.data == m)
            counts = mask.sum(axis=axis, keepdims=True)
            gg = _expand(out.grad, axis, keepdims, a.data.shape)
            a._accum(mask * gg / counts)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("min backward")  # TODO
+ added
        if a.requires_grad:
            m = a.data.min(axis=axis, keepdims=True)
            mask = (a.data == m)
            counts = mask.sum(axis=axis, keepdims=True)
            gg = _expand(out.grad, axis, keepdims, a.data.shape)
            a._accum(mask * gg / counts)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now shape ops:

/app/submission/autograd.py

− removed
        raise NotImplementedError("transpose backward")  # TODO
+ added
        if a.requires_grad:
            if axes is None:
                a._accum(np.transpose(out.grad))
            else:
                inv = np.argsort(axes)
                a._accum(np.transpose(out.grad, inv))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("reshape backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad.reshape(a.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("getitem backward")  # TODO
+ added
        if a.requires_grad:
            g = np.zeros_like(a.data)
            np.add.at(g, idx, out.grad)
            a._accum(g)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("concat backward")  # TODO
+ added
        g = out.grad
        offset = 0
        for t in ts:
            sz = t.data.shape[axis]
            sl = [slice(None)] * g.ndim
            sl[axis] = slice(offset, offset + sz)
            if t.requires_grad:
                t._accum(g[tuple(sl)])
            offset += sz

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("stack backward")  # TODO
+ added
        g = out.grad
        for i, t in enumerate(ts):
            sl = [slice(None)] * g.ndim
            sl[axis] = i
            if t.requires_grad:
                t._accum(g[tuple(sl)])

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("matmul backward")  # TODO
+ added
        g = out.grad
        if a.requires_grad:
            da = g @ np.swapaxes(b.data, -1, -2)
            a._accum(_unbroadcast(da, a.data.shape))
        if b.requires_grad:
            db = np.swapaxes(a.data, -1, -2) @ g
            b._accum(_unbroadcast(db, b.data.shape))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the nonlinearities:

/app/submission/autograd.py

− removed
        raise NotImplementedError("relu backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * (a.data > 0.0))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("leaky_relu backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * np.where(a.data > 0.0, 1.0, sl))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("sigmoid backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * s * (1.0 - s))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("tanh backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * (1.0 - t * t))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("softplus backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * (1.0 / (1.0 + np.exp(-bx))))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("silu backward")  # TODO
+ added
        if a.requires_grad:
            a._accum(out.grad * (s * (1.0 + x * (1.0 - s))))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("mish backward")  # TODO
+ added
        if a.requires_grad:
            sig = 1.0 / (1.0 + np.exp(-x))
            grad = t + x * (1.0 - t * t) * sig
            a._accum(out.grad * grad)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("elu backward")  # TODO
+ added
        if a.requires_grad:
            grad = np.where(pos, 1.0, al * np.exp(np.minimum(x, 0.0)))
            a._accum(out.grad * grad)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("logsumexp backward")  # TODO
+ added
        if a.requires_grad:
            sm = e / s
            gg = _expand(out.grad, axis, keepdims, a.data.shape)
            a._accum(sm * gg)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("var backward")  # TODO
+ added
        if a.requires_grad:
            N = _reduce_count(axis, x.shape)
            gg = _expand(out.grad, axis, keepdims, x.shape)
            a._accum(gg * (2.0 / N) * xc)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("std backward")  # TODO
+ added
        if a.requires_grad:
            N = _reduce_count(axis, x.shape)
            gg = _expand(out.grad, axis, keepdims, x.shape)
            a._accum(gg * xc / (N * sd))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("cumsum backward")  # TODO
+ added
        if a.requires_grad:
            gg = np.flip(out.grad, axis=axis)
            gg = np.cumsum(gg, axis=axis)
            gg = np.flip(gg, axis=axis)
            a._accum(gg)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("outer backward")  # TODO
+ added
        g = out.grad
        if a.requires_grad:
            a._accum(g @ b.data)
        if b.requires_grad:
            b._accum(a.data @ g)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("gelu backward")  # TODO
+ added
        if a.requires_grad:
            pdf = np.exp(-x * x / 2.0) / np.sqrt(2.0 * np.pi)
            a._accum(out.grad * (cdf + x * pdf))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("softmax backward")  # TODO
+ added
        if a.requires_grad:
            g = out.grad
            sm = out.data
            a._accum(sm * (g - (g * sm).sum(axis=axis, keepdims=True)))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("log_softmax backward")  # TODO
+ added
        if a.requires_grad:
            g = out.grad
            sm = np.exp(out.data)
            a._accum(g - sm * g.sum(axis=axis, keepdims=True))

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now losses, norms, embedding, dropout:

/app/submission/autograd.py

− removed
        raise NotImplementedError("cross_entropy backward")  # TODO
+ added
        if logits.requires_grad:
            sm = np.exp(logp)
            grad = sm.copy()
            grad[np.arange(n), t] -= 1.0
            grad = grad / n * out.grad
            logits._accum(grad)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("mse_loss backward")  # TODO
+ added
        if pred.requires_grad:
            pred._accum(2.0 * (pred.data - tgt) / pred.data.size * out.grad)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("layernorm backward")  # TODO
+ added
        g = out.grad
        D = x.shape[-1]
        if gamma.requires_grad:
            gamma._accum((g * xhat).reshape(-1, D).sum(0))
        if beta.requires_grad:
            beta._accum(g.reshape(-1, D).sum(0))
        if a.requires_grad:
            gx = g * gamma.data
            dx = inv / D * (D * gx - gx.sum(-1, keepdims=True)
                            - xhat * (gx * xhat).sum(-1, keepdims=True))
            a._accum(dx)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("batchnorm backward")  # TODO
+ added
        g = out.grad
        N = x.shape[0]
        if gamma.requires_grad:
            gamma._accum((g * xhat).sum(0))
        if beta.requires_grad:
            beta._accum(g.sum(0))
        if a.requires_grad:
            gx = g * gamma.data
            dx = inv / N * (N * gx - gx.sum(0, keepdims=True)
                            - xhat * (gx * xhat).sum(0, keepdims=True))
            a._accum(dx)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
        raise NotImplementedError("embedding backward")  # TODO
+ added
        if weight.requires_grad:
            g = np.zeros_like(weight.data)
            np.add.at(g, idx, out.grad)
            weight._accum(g)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
            raise NotImplementedError("dropout (eval) backward")  # TODO
+ added
            if a.requires_grad:
                a._accum(out.grad)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the dropout training path, and conv2d/maxpool2d/avgpool2d (forward+backward):

/app/submission/autograd.py

− removed
    raise NotImplementedError("dropout (training) -- optional")
+ added
    if rng is None:
        rng = np.random.default_rng()
    keep = 1.0 - p
    mask = (rng.random(a.data.shape) < keep).astype(np.float64) / keep
    out = _mk(a.data * mask, (a,), a.requires_grad)

    def _bw():
        if a.requires_grad:
            a._accum(out.grad * mask)

    out._backward = _bw
    return out

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
    TODO: implement the FORWARD and the backward. (Unlike the other ops, the forward is NOT
    pre-filled for you -- build the output, then differentiate it.)
    """
    raise NotImplementedError("conv2d")
+ added
    TODO: implement the FORWARD and the backward. (Unlike the other ops, the forward is NOT
    pre-filled for you -- build the output, then differentiate it.)
    """
    x = _ensure(x)
    weight = _ensure(weight)
    has_bias = bias is not None
    bt = _ensure(bias) if has_bias else None
    xd = x.data
    N, Cin, H, W = xd.shape
    Cout, Cin2, KH, KW = weight.data.shape
    s, p = stride, padding
    xp = _pad2d(xd, p)
    OH = (H + 2 * p - KH) // s + 1
    OW = (W + 2 * p - KW) // s + 1
    cols = np.zeros((N, Cin, KH, KW, OH, OW))
    for kh in range(KH):
        for kw in range(KW):
            cols[:, :, kh, kw, :, :] = xp[:, :, kh:kh + s * OH:s, kw:kw + s * OW:s]
    wcol = weight.data.reshape(Cout, Cin * KH * KW)
    colmat = cols.reshape(N, Cin * KH * KW, OH * OW)
    out_data = np.einsum('oc,ncp->nop', wcol, colmat).reshape(N, Cout, OH, OW)
    if has_bias:
        out_data = out_data + bt.data.reshape(1, Cout, 1, 1)
    parents = (x, weight, bt) if has_bias else (x, weight)
    rg = x.requires_grad or weight.requires_grad or (has_bias and bt.requires_grad)
    out = _mk(out_data, parents, rg)

    def _bw():
        g = out.grad
        gmat = g.reshape(N, Cout, OH * OW)
        if weight.requires_grad:
            dw = np.einsum('nop,ncp->oc', gmat, colmat).reshape(Cout, Cin, KH, KW)
            weight._accum(dw)
        if has_bias and bt.requires_grad:
            bt._accum(g.sum(axis=(0, 2, 3)))
        if x.requires_grad:
            dcol = np.einsum('oc,
…[truncated 382 chars]

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
    TODO: implement the FORWARD and the backward.
    """
    raise NotImplementedError("maxpool2d")
+ added
    TODO: implement the FORWARD and the backward.
    """
    x = _ensure(x)
    xd = x.data
    N, C, H, W = xd.shape
    k, s = kernel, stride
    OH = (H - k) // s + 1
    OW = (W - k) // s + 1
    wins = np.zeros((N, C, k, k, OH, OW))
    for kh in range(k):
        for kw in range(k):
            wins[:, :, kh, kw, :, :] = xd[:, :, kh:kh + s * OH:s, kw:kw + s * OW:s]
    winsf = wins.reshape(N, C, k * k, OH, OW)
    out_data = winsf.max(axis=2)
    out = _mk(out_data, (x,), x.requires_grad)

    def _bw():
        if not x.requires_grad:
            return
        g = out.grad
        m = winsf.max(axis=2, keepdims=True)
        mask = (winsf == m)
        counts = mask.sum(axis=2, keepdims=True)
        dwin = mask * (g[:, :, None, :, :]) / counts
        dwin = dwin.reshape(N, C, k, k, OH, OW)
        dx = np.zeros_like(xd)
        for kh in range(k):
            for kw in range(k):
                dx[:, :, kh:kh + s * OH:s, kw:kw + s * OW:s] += dwin[:, :, kh, kw, :, :]
        x._accum(dx)

    out._backward = _bw
    return out

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
    TODO: implement the FORWARD and the backward.
    """
    raise NotImplementedError("avgpool2d")
+ added
    TODO: implement the FORWARD and the backward.
    """
    x = _ensure(x)
    xd = x.data
    N, C, H, W = xd.shape
    k, s = kernel, stride
    OH = (H - k) // s + 1
    OW = (W - k) // s + 1
    wins = np.zeros((N, C, k, k, OH, OW))
    for kh in range(k):
        for kw in range(k):
            wins[:, :, kh, kw, :, :] = xd[:, :, kh:kh + s * OH:s, kw:kw + s * OW:s]
    out_data = wins.reshape(N, C, k * k, OH, OW).mean(axis=2)
    out = _mk(out_data, (x,), x.requires_grad)

    def _bw():
        if not x.requires_grad:
            return
        g = out.grad / (k * k)
        dx = np.zeros_like(xd)
        for kh in range(k):
            for kw in range(k):
                dx[:, :, kh:kh + s * OH:s, kw:kw + s * OW:s] += g
        x._accum(dx)

    out._backward = _bw
    return out

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
autograd.py is done. Let me run the autograd checks before continuing:
shell
python3 run_checks.py --only autograd_grads 2>&1 | tail -20
output
grad/nn.LayerNorm_x                  FAIL  (raised NotImplementedError: LayerNorm.forward)
  grad/nn.BatchNorm1d_x                FAIL  (raised NotImplementedError: BatchNorm1d.forward)
  grad/nn.HiddenBlock_x                FAIL  (raised NotImplementedError: HiddenBlock.forward)
  grad/nn.MLP_x                        FAIL  (raised NotImplementedError: MLP.forward)
  grad/nn.MHA_x                        FAIL  (raised NotImplementedError: MultiHeadSelfAttention.forward)
  grad/nn.Conv2d_x                     FAIL  (raised NotImplementedError: Conv2d.forward)
  grad/nn.MaxPool2d_x                  FAIL  (raised NotImplementedError: MaxPool2d.forward)
  grad/nn.AvgPool2d_x                  FAIL  (raised NotImplementedError: AvgPool2d.forward)
  grad/nn.RNNCell_x                    FAIL  (raised NotImplementedError: RNNCell.forward)
  grad/nn.LSTMCell_x                   FAIL  (raised NotImplementedError: LSTMCell.forward)
  grad/nn.GRUCell_x                    FAIL  (raised NotImplementedError: GRUCell.forward)
  grad/clf_head.bias                   FAIL  (raised NotImplementedError: MLPClassifier.forward)
  grad/clf_layers.0.fc.weight          FAIL  (raised NotImplementedError: MLPClassifier.forward)
  grad/clf_layers.1.ln.gamma           FAIL  (raised NotImplementedError: MLPClassifier.forward)
  grad/clf_layers.0.fc.bias            FAIL  (raised NotImplementedError: MLPClassifier.forward)

----------------------------------------------------------------------
autograd_grads
…[truncated 165 chars]
The pure autograd ops pass. Let me check there are no op-level failures:
shell
python3 run_checks.py --only autograd_grads 2>&1 | grep FAIL | grep -v "nn\.\|clf_"
output
Fix the FAIL lines above (each is a backward/forward/optimizer/SSL bug). Re-run this until everything is green, then train.
All pure autograd ops pass. Now let me implement `nn.py`. Let me edit each forward:

/app/submission/nn.py

− removed
        # TODO: matmul x@weight then add bias (if present). Use ag.matmul / ag.add.
        raise NotImplementedError("Linear.forward")
+ added
        out = ag.matmul(x, self.weight)
        if self.bias is not None:
            out = ag.add(out, self.bias)
        return out

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: return ag.embedding(self.weight, idx)
        raise NotImplementedError("Embedding.forward")
+ added
        return ag.embedding(self.weight, idx)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: return ag.layernorm(x, self.gamma, self.beta, self.eps)
        raise NotImplementedError("LayerNorm.forward")
+ added
        return ag.layernorm(x, self.gamma, self.beta, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: ms = mean(x*x, -1, keepdims); inv = (ms+eps)**-0.5; return x*inv*gamma  (autograd ops)
        raise NotImplementedError("RMSNorm.forward")
+ added
        ms = ag.mean(ag.mul(x, x), axis=-1, keepdims=True)
        inv = ag.power(ag.add(ms, self.eps), -0.5)
        return ag.mul(ag.mul(x, inv), self.gamma)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: g = ag.silu(self.w_gate(x)); u = self.w_up(x); return self.w_down(ag.mul(g, u))
        raise NotImplementedError("SwiGLU.forward")
+ added
        g = ag.silu(self.w_gate(x))
        u = self.w_up(x)
        return self.w_down(ag.mul(g, u))

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: return ag.batchnorm(x, self.gamma, self.beta, self.eps)
        raise NotImplementedError("BatchNorm1d.forward")
+ added
        return ag.batchnorm(x, self.gamma, self.beta, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: return ag.dropout(x, self.p, training, rng)
        raise NotImplementedError("Dropout.forward")
+ added
        return ag.dropout(x, self.p, training, rng)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: return ag.conv2d(x, self.weight, self.bias, self.stride, self.padding)
        raise NotImplementedError("Conv2d.forward")
+ added
        return ag.conv2d(x, self.weight, self.bias, self.stride, self.padding)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: return ag.maxpool2d(x, self.kernel, self.stride)
        raise NotImplementedError("MaxPool2d.forward")
+ added
        return ag.maxpool2d(x, self.kernel, self.stride)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: return ag.avgpool2d(x, self.kernel, self.stride)
        raise NotImplementedError("AvgPool2d.forward")
+ added
        return ag.avgpool2d(x, self.kernel, self.stride)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now MHA, MLP, TransformerBlock:

/app/submission/nn.py

− removed
        # TODO: implement causal multi-head self-attention as described in the docstring.
        raise NotImplementedError("MultiHeadSelfAttention.forward")
+ added
        B, T, _ = x.shape
        nh, dh = self.n_head, self.d_head
        qkv = self.qkv(x)                                    # (B,T,3*d_model)
        qkv = ag.reshape(qkv, (B, T, 3, nh, dh))
        qkv = ag.transpose(qkv, (2, 0, 3, 1, 4))             # (3,B,nh,T,dh)
        q, k, v = qkv[0], qkv[1], qkv[2]                     # (B,nh,T,dh)
        kt = ag.transpose(k, (0, 1, 3, 2))                   # (B,nh,dh,T)
        scores = ag.mul(ag.matmul(q, kt), 1.0 / np.sqrt(dh))  # (B,nh,T,T)
        mask = np.triu(np.ones((T, T)), k=1) * (-1e9)
        scores = ag.add(scores, Tensor(mask))
        att = ag.softmax(scores, axis=-1)
        out = ag.matmul(att, v)                              # (B,nh,T,dh)
        out = ag.transpose(out, (0, 2, 1, 3))                # (B,T,nh,dh)
        out = ag.reshape(out, (B, T, self.d_model))
        return self.proj(out)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: fc2(gelu(fc1(x)))
        raise NotImplementedError("MLP.forward")
+ added
        return self.fc2(ag.gelu(self.fc1(x)))

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: pre-norm residual wiring (see docstring).
        raise NotImplementedError("TransformerBlock.forward")
+ added
        x = ag.add(x, self.attn(self.ln1(x)))
        x = ag.add(x, self.mlp(self.ln2(x)))
        return x

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the recurrent cells:

/app/submission/nn.py

− removed
        # TODO: tanh(x@W_ih + b_ih + h@W_hh + b_hh)
        raise NotImplementedError("RNNCell.forward")
+ added
        a = ag.add(ag.matmul(x, self.W_ih), self.b_ih)
        b = ag.add(ag.matmul(h, self.W_hh), self.b_hh)
        return ag.tanh(ag.add(a, b))

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: implement the LSTM cell update; return (h_new, c_new).
        raise NotImplementedError("LSTMCell.forward")
+ added
        h, c = state
        H = self.hidden
        z = ag.add(ag.add(ag.matmul(x, self.W_ih), self.b_ih),
                   ag.add(ag.matmul(h, self.W_hh), self.b_hh))
        i = ag.sigmoid(z[:, 0:H])
        f = ag.sigmoid(z[:, H:2 * H])
        g = ag.tanh(z[:, 2 * H:3 * H])
        o = ag.sigmoid(z[:, 3 * H:4 * H])
        c_new = ag.add(ag.mul(f, c), ag.mul(i, g))
        h_new = ag.mul(o, ag.tanh(c_new))
        return h_new, c_new

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: implement the GRU cell update; return h_new.
        raise NotImplementedError("GRUCell.forward")
+ added
        H = self.hidden
        gi = ag.add(ag.matmul(x, self.W_ih), self.b_ih)
        gh = ag.add(ag.matmul(h, self.W_hh), self.b_hh)
        r = ag.sigmoid(ag.add(gi[:, 0:H], gh[:, 0:H]))
        z = ag.sigmoid(ag.add(gi[:, H:2 * H], gh[:, H:2 * H]))
        n = ag.tanh(ag.add(gi[:, 2 * H:3 * H], ag.mul(r, gh[:, 2 * H:3 * H])))
        h_new = ag.add(ag.mul(ag.sub(1.0, z), n), ag.mul(z, h))
        return h_new

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the models: HiddenBlock, MLPClassifier, CNNClassifier, SeqClassifier:

/app/submission/nn.py

− removed
        # TODO: relu(layernorm(linear(x))) -- compose self.fc, self.ln and ag.relu.
        raise NotImplementedError("HiddenBlock.forward")
+ added
        return ag.relu(self.ln(self.fc(x)))

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: h = Tensor(X) if X is a raw array; for blk in self.layers: h = blk(h);
        #       return self.head(h)
        raise NotImplementedError("MLPClassifier.forward")
+ added
        h = X if isinstance(X, Tensor) else Tensor(X)
        for blk in self.layers:
            h = blk(h)
        return self.head(h)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: implement the conv->relu->maxpool x2 -> flatten -> fc pipeline (see docstring).
        #       Wrap a raw ndarray x in a Tensor first; reshape with the batch size N as dim 0.
        raise NotImplementedError("CNNClassifier.forward")
+ added
        h = x if isinstance(x, Tensor) else Tensor(x)
        N = h.shape[0]
        h = ag.maxpool2d(ag.relu(self.conv1(h)), 2, 2)
        h = ag.maxpool2d(ag.relu(self.conv2(h)), 2, 2)
        h = ag.reshape(h, (N, self.feat))
        return self.fc(h)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
        # TODO: embed idx, loop the cell over time from a zero state, classify the final hidden.
        raise NotImplementedError("SeqClassifier.forward")
+ added
        idx = np.asarray(idx)
        N, T = idx.shape
        emb = self.embed(idx)                       # (N, T, d_model)
        h = Tensor(np.zeros((N, self.hidden)))
        c = Tensor(np.zeros((N, self.hidden)))
        for t in range(T):
            xt = emb[:, t, :]
            if self.cell_kind == "lstm":
                h, c = self.cell(xt, (h, c))
            else:
                h = self.cell(xt, h)
        return self.fc(h)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only autograd_grads 2>&1 | tail -5 && echo "===NN===" && python3 run_checks.py --only nn_forward 2>&1 | tail -25
output
----------------------------------------------------------------------
autograd_grads 77/77
TOTAL  77/77 public checks passing
All public checks pass. Now make sure model.npz clears the held-out test threshold, and remember the grader re-checks with DIFFERENT seeds/shapes.
===NN===
  fwd/softmax_sums_to_1                OK    (row_sum_err=1.1e-16)
  fwd/log_softmax_eq_log_softmax       OK  
  fwd/relu_def                         OK  
  fwd/sigmoid_def                      OK  
  fwd/tanh_def                         OK  
  fwd/gelu_erf_def                     OK  
  fwd/softplus_def                     OK  
  fwd/silu_def                         OK  
  fwd/logsumexp_def                    OK  
  fwd/rmsnorm_unit_rms                 OK  
  fwd/cross_entropy_value              OK    (got=3.2296 ref=3.2296)
  fwd/layernorm_zero_mean_unit_var     OK  
  fwd/batchnorm_zero_mean_unit_var     OK  
  fwd/Linear_def                       OK  
  fwd/Conv2d_shape                     OK    (shape=(2, 5, 8, 8))
  fwd/MHA_shape                        OK    (shape=(2, 4, 8))
  fwd/MHA_causal                       OK    (pos0 drift=0.0e+00 (must be ~0: causal))
  fwd/MLPClassifier_shape              OK  
  fwd/CNN_shape                        OK  
  fwd/Seq_shape                        OK  

----------------------------------------------------------------------
nn_forward 20/20
TOTAL  20/20 public checks passing
All public checks pass. Now make sure model.npz clears the held-out test threshol
…[truncated 65 chars]
autograd and nn_forward fully pass. Now optim.py:

/app/submission/optim.py

− removed
        # TODO: SGD(+momentum, +coupled weight decay, +optional Nesterov) update.
        raise NotImplementedError("SGD.step")
+ added
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._v[i] = self.momentum * self._v[i] + g
            upd = (g + self.momentum * self._v[i]) if self.nesterov else self._v[i]
            p.data -= self.lr * upd

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
        # TODO: Adagrad update (accumulate squared grads).
        raise NotImplementedError("Adagrad.step")
+ added
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._s[i] = self._s[i] + g * g
            p.data -= self.lr * g / (np.sqrt(self._s[i]) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
        # TODO: RMSprop update (EMA of squared grads).
        raise NotImplementedError("RMSprop.step")
+ added
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._s[i] = self.alpha * self._s[i] + (1 - self.alpha) * (g * g)
            p.data -= self.lr * g / (np.sqrt(self._s[i]) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
        # TODO: Adam update with bias correction + COUPLED (L2) weight decay.
        raise NotImplementedError("Adam.step")
+ added
        self.t += 1
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._v[i] = self.b2 * self._v[i] + (1 - self.b2) * (g * g)
            mhat = self._m[i] / (1 - self.b1 ** self.t)
            vhat = self._v[i] / (1 - self.b2 ** self.t)
            p.data -= self.lr * mhat / (np.sqrt(vhat) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
        # TODO: AdamW update with bias correction + DECOUPLED weight decay.
        raise NotImplementedError("AdamW.step")
+ added
        self.t += 1
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._v[i] = self.b2 * self._v[i] + (1 - self.b2) * (g * g)
            mhat = self._m[i] / (1 - self.b1 ** self.t)
            vhat = self._v[i] / (1 - self.b2 ** self.t)
            p.data -= self.lr * (mhat / (np.sqrt(vhat) + self.eps) + self.weight_decay * p.data)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
        # TODO: Lion update (sign of interpolated momentum; momentum updated AFTER the step).
        raise NotImplementedError("Lion.step")
+ added
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad
            upd = np.sign(self.b1 * self._m[i] + (1 - self.b1) * g)
            p.data -= self.lr * (upd + self.weight_decay * p.data)
            self._m[i] = self.b2 * self._m[i] + (1 - self.b2) * g

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    # TODO: compute the global L2 norm over all param grads; scale in place if it exceeds max_norm.
    raise NotImplementedError("clip_grad_norm")
+ added
    total = 0.0
    for p in params:
        if p.grad is not None:
            total += float((p.grad ** 2).sum())
    total = math.sqrt(total)
    if total > max_norm:
        scale = max_norm / (total + 1e-6)
        for p in params:
            if p.grad is not None:
                p.grad = p.grad * scale
    return total

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the schedulers:

/app/submission/optim.py

− removed
    # TODO
    raise NotImplementedError("cosine_lr")
+ added
    if warmup > 0 and step < warmup:
        return base_lr * (step + 1) / warmup
    prog = min(1.0, max(0.0, (step - warmup) / max(1, total - warmup)))
    return min_lr + 0.5 * (base_lr - min_lr) * (1.0 + math.cos(math.pi * prog))

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    # TODO
    raise NotImplementedError("step_lr")
+ added
    return base_lr * gamma ** (step // step_size)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    # TODO
    raise NotImplementedError("exponential_lr")
+ added
    return base_lr * gamma ** step

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    # TODO
    raise NotImplementedError("warmup_lr")
+ added
    if step < warmup:
        return base_lr * (step + 1) / warmup
    return base_lr

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only optim 2>&1 | tail -20
output
optim/SGD_momentum_5step             OK    (max_abs=0.0e+00)
  optim/SGD_nesterov_5step             OK    (max_abs=0.0e+00)
  optim/Adagrad_5step                  OK    (max_abs=0.0e+00)
  optim/RMSprop_5step                  OK    (max_abs=0.0e+00)
  optim/Adam_1step                     OK    (max_abs=0.0e+00)
  optim/Adam_10step_wd                 OK    (max_abs=0.0e+00)
  optim/AdamW_1step                    OK    (max_abs=0.0e+00)
  optim/AdamW_10step_wd                OK    (max_abs=0.0e+00)
  optim/Lion_5step                     OK    (max_abs=0.0e+00)
  optim/clip_grad_norm_clips           OK    (max_abs=0.0e+00)
  optim/clip_grad_norm_noop            OK    (max_abs=0.0e+00)
  optim/sched_cosine                   OK    (max_abs=0.0e+00)
  optim/sched_warmup                   OK    (max_abs=0.0e+00)
  optim/sched_step                     OK    (max_abs=0.0e+00)
  optim/sched_exponential              OK    (max_abs=0.0e+00)

----------------------------------------------------------------------
optim 16/16
TOTAL  16/16 public checks passing
All public checks pass. Now make sure model.npz clears the held-out test threshold, and remember the grader re-checks with DIFFERENT seeds/shapes.
optim fully passes. Now data.py:

/app/submission/data.py

− removed
    # TODO: np.load the file; return (X as float64, y as int64 reshaped to 1-D or None if absent).
    raise NotImplementedError("load_npz")
+ added
    d = np.load(path)
    X = np.asarray(d["X"], dtype=np.float64)
    y = None
    if "y" in d.files:
        y = np.asarray(d["y"], dtype=np.int64).reshape(-1)
    return X, y

contents
The file /app/submission/data.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/data.py

− removed
    # TODO: return int(max(y)) + 1
    raise NotImplementedError("n_classes")
+ added
    return int(np.max(y)) + 1

contents
The file /app/submission/data.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/data.py

− removed
    # TODO: yield successive slices of a single rng.permutation(n) of size batch_size.
    raise NotImplementedError("epoch_batches")
+ added
    perm = rng.permutation(n)
    for start in range(0, n, batch_size):
        yield perm[start:start + batch_size]

contents
The file /app/submission/data.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/data.py

− removed
    # TODO: gather X[idx] (float64) and y[idx] (int64, or None if y is None); return (Xb, yb, idx).
    raise NotImplementedError("get_batch")
+ added
    idx = np.asarray(idx, dtype=np.int64)
    Xb = np.asarray(X[idx], dtype=np.float64)
    yb = None if y is None else np.asarray(y[idx], dtype=np.int64)
    return Xb, yb, idx

contents
The file /app/submission/data.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/data.py

− removed
    # TODO: build per-class templates, pick labels, return template[y] + noise and the labels.
    raise NotImplementedError("make_image_dataset")
+ added
    rng = np.random.default_rng(seed)
    templates = rng.standard_normal((n_classes, 1, img, img))
    y = rng.integers(0, n_classes, size=n)
    X = templates[y] + rng.standard_normal((n, 1, img, img)) * 0.3
    return np.asarray(X, dtype=np.float64), np.asarray(y, dtype=np.int64)

contents
The file /app/submission/data.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/data.py

− removed
    # TODO: sample (n, T) token ids in [0, vocab); label = (row sum) % n_classes.
    raise NotImplementedError("make_seq_dataset")
+ added
    rng = np.random.default_rng(seed)
    X = rng.integers(0, vocab, size=(n, T))
    y = X.sum(axis=1) % n_classes
    return np.asarray(X, dtype=np.int64), np.asarray(y, dtype=np.int64)

contents
The file /app/submission/data.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now ssl.py , the densest part. Let me implement augmentation/gating first:

/app/submission/ssl.py

− removed
    # TODO: return X + rng.normal(0, sigma, X.shape)  (X as float64)
    raise NotImplementedError("weak_augment")
+ added
    X = np.asarray(X, dtype=np.float64)
    return X + rng.normal(0.0, sigma, X.shape)

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: add jitter, then for each row zero round(mask_frac*dim) randomly-chosen coordinates.
    raise NotImplementedError("strong_augment")
+ added
    X = np.asarray(X, dtype=np.float64)
    out = X + rng.normal(0.0, sigma, X.shape)
    n, dim = out.shape
    k = int(round(mask_frac * dim))
    if k > 0:
        for i in range(n):
            idx = rng.choice(dim, size=k, replace=False)
            out[i, idx] = 0.0
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: copy X; for each row pick a random start and zero [start:start+length].
    raise NotImplementedError("cutout")
+ added
    out = np.asarray(X, dtype=np.float64).copy()
    n, dim = out.shape
    for i in range(n):
        start = int(rng.integers(0, dim))
        out[i, start:start + length] = 0.0
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: implement the convex combination described above; return (X_mix, y_mix, lam, perm).
    raise NotImplementedError("mixup")
+ added
    X = np.asarray(X, dtype=np.float64)
    onehot = np.asarray(onehot, dtype=np.float64)
    lam = float(rng.beta(alpha, alpha))
    lam = max(lam, 1.0 - lam)
    perm = rng.permutation(X.shape[0])
    X_mix = lam * X + (1.0 - lam) * X[perm]
    y_mix = lam * onehot + (1.0 - lam) * onehot[perm]
    return X_mix, y_mix, lam, perm

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: stack to (K, M, ...), swap the leading block axis with K over full blocks, return list.
    raise NotImplementedError("interleave")
+ added
    K = len(arrays)
    M = arrays[0].shape[0]
    nb = M // batch_size
    rest = arrays[0].shape[1:]
    perm = (1, 0, 2) + tuple(range(3, 3 + len(rest)))
    s = np.stack(arrays, axis=0).reshape((K, nb, batch_size) + rest)
    s = s.transpose(perm)                                    # (nb, K, batch, ...)
    s = s.reshape((K, nb, batch_size) + rest)                # reinterpret
    return [s[i].reshape((M,) + rest) for i in range(K)]

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: invert the interleave permutation.
    raise NotImplementedError("de_interleave")
+ added
    K = len(arrays)
    M = arrays[0].shape[0]
    nb = M // batch_size
    rest = arrays[0].shape[1:]
    perm = (1, 0, 2) + tuple(range(3, 3 + len(rest)))
    s = np.stack(arrays, axis=0).reshape((K, nb, batch_size) + rest)   # C
    s = s.reshape((nb, K, batch_size) + rest)                          # B
    s = s.transpose(perm)                                              # A: (K, nb, batch, ...)
    return [s[i].reshape((M,) + rest) for i in range(K)]

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: compute hard/conf/mask/onehot as above.
    raise NotImplementedError("pseudo_label")
+ added
    weak_probs = np.asarray(weak_probs, dtype=np.float64)
    n = weak_probs.shape[0]
    hard = weak_probs.argmax(axis=1)
    conf = weak_probs.max(axis=1)
    mask = (conf >= tau).astype(np.float64)
    onehot = np.zeros_like(weak_probs)
    onehot[np.arange(n), hard] = 1.0
    return onehot, mask, hard

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: return (probs.max(axis=1) >= tau).astype(float)
    raise NotImplementedError("confidence_mask")
+ added
    probs = np.asarray(probs, dtype=np.float64)
    return (probs.max(axis=1) >= tau).astype(np.float64)

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: pw = probs ** (1/temperature); return pw / pw.sum(axis=1, keepdims=True)
    raise NotImplementedError("sharpen")
+ added
    probs = np.asarray(probs, dtype=np.float64)
    pw = probs ** (1.0 / temperature)
    return pw / pw.sum(axis=1, keepdims=True)

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
        # TODO: update self.value with the EMA recursion and return it.
        raise NotImplementedError("EMAScalar.update")
+ added
        self.value = self.decay * self.value + (1.0 - self.decay) * float(new)
        return self.value

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
        # TODO: update self.running, rescale by prior/(running+1e-6), renormalize rows, return.
        raise NotImplementedError("DistributionAligner.align")
+ added
        weak_probs = np.asarray(weak_probs, dtype=np.float64)
        self.running = self.momentum * self.running + (1.0 - self.momentum) * weak_probs.mean(axis=0)
        aligned = weak_probs * (self.prior / (self.running + 1e-6))
        aligned = aligned / aligned.sum(axis=1, keepdims=True)
        return aligned

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
        # TODO: compute sigma (per-class confident-argmax counts), set self.sigma, return beta*tau
        # with denom = max(sigma.max(), C - sigma.sum()) (guard against 0).
        raise NotImplementedError("FlexMatchThresholder.update")
+ added
        p = np.asarray(weak_probs, dtype=np.float64)
        hard = p.argmax(axis=1)
        conf = p.max(axis=1)
        adm = conf >= self.tau
        sig = np.array([float(np.sum(adm & (hard == c))) for c in range(self.C)])
        self.sigma = sig
        denom = max(float(sig.max()), float(self.C - sig.sum()))
        if denom <= 0:
            denom = 1.0
        return (sig / denom) * self.tau

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
        # TODO: thr = self.update(weak_probs); return (max prob per row >= thr[argmax]) as 0/1 float.
        raise NotImplementedError("FlexMatchThresholder.flex_mask")
+ added
        p = np.asarray(weak_probs, dtype=np.float64)
        thr = self.update(p)
        hard = p.argmax(axis=1)
        conf = p.max(axis=1)
        return (conf >= thr[hard]).astype(np.float64)

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: clip(step/length, 0, 1) (handle length<=0 -> 1.0).
    raise NotImplementedError("linear_rampup")
+ added
    if length <= 0:
        return 1.0
    return float(np.clip(step / length, 0.0, 1.0))

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: per the docstring (1.0 once step>=length).
    raise NotImplementedError("cosine_rampup")
+ added
    if length <= 0:
        return 1.0
    x = float(np.clip(step / length, 0.0, 1.0))
    return 0.5 * (1.0 - np.cos(np.pi * x))

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: per the docstring.
    raise NotImplementedError("exp_rampup")
+ added
    if length <= 0:
        return 1.0
    x = float(np.clip(step / length, 0.0, 1.0))
    return float(np.exp(-5.0 * (1.0 - x) ** 2))

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: build the (N,C) complementary one-hot on argmin for confident rows only.
    raise NotImplementedError("complement_distribution")
+ added
    p = np.asarray(weak_probs, dtype=np.float64)
    n = p.shape[0]
    conf = p.max(axis=1)
    least = p.argmin(axis=1)
    sel = conf >= tau
    out = np.zeros_like(p)
    rows = np.arange(n)[sel]
    out[rows, least[sel]] = 1.0
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the differentiable loss ops. Let me implement soft_cross_entropy:

/app/submission/ssl.py

− removed
    # TODO: forward value via _stable_log_softmax_np; build out via _mk(val, (logits,)); set out._backward.
    raise NotImplementedError("soft_cross_entropy")
+ added
    logp = _stable_log_softmax_np(x)
    per = -(tgt * logp).sum(axis=1)
    val = (w * per).sum() / n
    out = _mk(val, (logits,))

    def _bw():
        s = _stable_softmax_np(x)
        tsum = tgt.sum(axis=1, keepdims=True)
        grad = (w[:, None] / n) * (s * tsum - tgt)
        logits._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: forward (sum of squared diffs, weighted, /N); backward through the softmax (see docstring).
    raise NotImplementedError("mse_consistency")
+ added
    s = _stable_softmax_np(x)
    diff = s - tgt
    per = (diff * diff).sum(axis=1)
    val = (w * per).sum() / n
    out = _mk(val, (student_logits,))

    def _bw():
        v = (2.0 * w[:, None] / n) * diff
        grad = s * (v - (v * s).sum(axis=1, keepdims=True))
        student_logits._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: forward (include the teacher-entropy term so KL is reported); backward as above.
    raise NotImplementedError("kl_divergence")
+ added
    logp = _stable_log_softmax_np(x)
    tlog = np.where(tgt > 0, np.log(np.clip(tgt, 1e-12, None)), 0.0)
    per = (tgt * (tlog - logp)).sum(axis=1)
    val = (w * per).sum() / n
    out = _mk(val, (student_logits,))

    def _bw():
        s = _stable_softmax_np(x)
        tsum = tgt.sum(axis=1, keepdims=True)
        grad = (w[:, None] / n) * (s * tsum - tgt)
        student_logits._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: forward mean entropy; backward per the docstring.
    raise NotImplementedError("entropy_loss")
+ added
    logp = _stable_log_softmax_np(x)
    p = np.exp(logp)
    H = -(p * logp).sum(axis=1)
    val = H.sum() / n
    out = _mk(val, (logits,))

    def _bw():
        Hk = H[:, None]
        grad = (1.0 / n) * p * (-logp - Hk)
        logits._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: forward (-H of the batch marginal); backward per the docstring.
    raise NotImplementedError("class_balance_loss")
+ added
    p = _stable_softmax_np(x)
    pbar = p.mean(axis=0)
    val = (pbar * np.log(np.clip(pbar, 1e-12, None))).sum()
    out = _mk(val, (logits,))

    def _bw():
        a = 1.0 + np.log(np.clip(pbar, 1e-12, None))
        ap = (p * a[None, :]).sum(axis=1, keepdims=True)
        grad = (1.0 / n) * p * (a[None, :] - ap)
        logits._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: stable sigmoid-BCE forward via _mk(val, (z,)); backward (w/N)*(sigmoid(z)-t).
    raise NotImplementedError("bce_consistency")
+ added
    per = (np.maximum(x, 0.0) - x * t + np.log1p(np.exp(-np.abs(x)))).sum(axis=1)
    val = (w * per).sum() / n
    out = _mk(val, (z,))

    def _bw():
        s = 1.0 / (1.0 + np.exp(-x))
        grad = (w[:, None] / n) * (s - t)
        z._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: forward sum-squared-diff averaged over N; backward (2w/N)*(x-t).
    raise NotImplementedError("pi_consistency")
+ added
    diff = x - t
    per = (diff * diff).sum(axis=1)
    val = (w * per).sum() / n
    out = _mk(val, (z,))

    def _bw():
        grad = (2.0 * w[:, None] / n) * diff
        z._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: forward via _stable_log_softmax_np; backward through softmax per the docstring.
    raise NotImplementedError("focal_consistency")
+ added
    logp = _stable_log_softmax_np(x)
    p = np.exp(logp)
    omp = 1.0 - p
    nlogp = -logp
    omp_g = omp ** gm
    per = (t * omp_g * nlogp).sum(axis=1)
    val = (w * per).sum() / n
    out = _mk(val, (z,))

    def _bw():
        if gm == 0.0:
            term1 = np.zeros_like(p)
        else:
            term1 = -gm * (omp ** (gm - 1.0)) * nlogp
        u = t * (term1 - omp_g / p)
        up = (u * p).sum(axis=1, keepdims=True)
        grad = (w[:, None] / n) * p * (u - up)
        z._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: forward JS (clip probs to 1e-12 before log); backward through softmax per the docstring.
    raise NotImplementedError("js_divergence")
+ added
    p = _stable_softmax_np(x)
    pc = np.clip(p, 1e-12, None)
    tc = np.clip(t, 1e-12, None)
    m = 0.5 * (p + t)
    mc = np.clip(m, 1e-12, None)
    per = 0.5 * (p * (np.log(pc) - np.log(mc))).sum(axis=1) \
        + 0.5 * (t * (np.log(tc) - np.log(mc))).sum(axis=1)
    val = (w * per).sum() / n
    out = _mk(val, (z,))

    def _bw():
        u = (w[:, None] / n) * 0.5 * (np.log(pc) - np.log(mc))
        up = (u * p).sum(axis=1, keepdims=True)
        grad = p * (u - up)
        z._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: forward -(comp*log(1-p)) (clip 1-p to 1e-12); backward through softmax per the docstring.
    raise NotImplementedError("negative_consistency")
+ added
    p = _stable_softmax_np(x)
    omp = np.clip(1.0 - p, 1e-12, None)
    per = -(comp * np.log(omp)).sum(axis=1)
    val = (w * per).sum() / n
    out = _mk(val, (z,))

    def _bw():
        u = comp / omp
        up = (u * p).sum(axis=1, keepdims=True)
        grad = (w[:, None] / n) * p * (u - up)
        z._accum(grad * out.grad)

    out._backward = _bw
    return out

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now consistency_loss, fixmatch_loss, and EMATeacher:

/app/submission/ssl.py

− removed
    # TODO: onehot, mask = pseudo_label(...); loss = soft_cross_entropy(...); scale by lambda_u.
    raise NotImplementedError("consistency_loss")
+ added
    weak_probs = np.asarray(weak_probs, dtype=np.float64)
    onehot, mask, hard = pseudo_label(weak_probs, tau)
    loss = soft_cross_entropy(strong_logits, onehot, weight=mask)
    loss = ag.mul(loss, float(lambda_u))
    mask_rate = float(mask.mean())
    return loss, mask_rate

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
    # TODO: sup = ag.cross_entropy(...); cons, mr = consistency_loss(...); return (ag.add(sup, cons), mr).
    raise NotImplementedError("fixmatch_loss")
+ added
    sup = ag.cross_entropy(sup_logits, sup_y)
    cons, mr = consistency_loss(strong_logits, weak_probs, tau, lambda_u=lambda_u)
    return ag.add(sup, cons), mr

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
        # TODO: for each named param, shadow <- decay*shadow + (1-decay)*param.data (in place).
        raise NotImplementedError("EMATeacher.update")
+ added
        for k, v in model.named_params().items():
            self.shadow[k] = self.decay * self.shadow[k] + (1.0 - self.decay) * v.data

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/ssl.py

− removed
        # TODO: write self.shadow[k] into each model param's data.
        raise NotImplementedError("EMATeacher.copy_to")
+ added
        for k, v in model.named_params().items():
            v.data[...] = self.shadow[k]

contents
The file /app/submission/ssl.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only fixmatch 2>&1 | tail -45
output
[fixmatch]  31/31
  fixmatch/sce_bwd_onehot              OK    (max_abs=2.72e-11)
  fixmatch/sce_bwd_soft                OK    (max_abs=3.07e-11)
  fixmatch/mse_consistency_bwd         OK    (max_abs=2.91e-12)
  fixmatch/kl_divergence_bwd           OK    (max_abs=1.02e-11)
  fixmatch/entropy_loss_bwd            OK    (max_abs=1.93e-11)
  fixmatch/class_balance_bwd           OK    (max_abs=2.09e-11)
  fixmatch/bce_consistency_bwd         OK    (max_abs=9.43e-12)
  fixmatch/pi_consistency_bwd          OK    (max_abs=8.00e-11)
  fixmatch/focal_bwd_onehot            OK    (max_abs=8.93e-12)
  fixmatch/focal_bwd_soft              OK    (max_abs=1.15e-11)
  fixmatch/js_divergence_bwd           OK    (max_abs=1.39e-12)
  fixmatch/negative_consistency_bwd    OK    (max_abs=7.06e-12)
  fixmatch/flexmatch_threshold         OK  
  fixmatch/rampup_schedules            OK  
  fixmatch/complement_distribution     OK  
  fixmatch/cons_bwd_tau0.3             OK    (max_abs=2.06e-11)
  fixmatch/cons_bwd_tau0.5             OK    (max_abs=0.00e+00)
  fixmatch/cons_mask_all_zero          OK  
  fixmatch/pseudo_label_gate           OK  
  fixmatch/pseudo_label_boundary       OK  
  fixmatch/confidence_mask             OK  
  fixmatch/sharpen_T0.5                OK  
  fixmatch/sharpen_T2.0                OK  
  fixmatch/sharpen_identity            OK  
  fixmatch/mixup_convex                OK    (lam=0.904)
  fixmatch/interleave_roundtrip        OK  
  fixmatch/da_recursion                OK  
 
…[truncated 443 chars]
All fixmatch checks pass. Let me run the full suite including integration and data:
shell
python3 run_checks.py 2>&1 | tail -12
output
integration/fixmatch_decreases       OK    (3.4580->2.3232)

[data]  4/4
  data/load_npz                        OK  
  data/epoch_batches                   OK  
  data/make_image_dataset              OK    (X=(20, 1, 8, 8))
  data/make_seq_dataset                OK    (X=(20, 12))

----------------------------------------------------------------------
autograd_grads 77/77 | nn_forward 20/20 | optim 16/16 | fixmatch 31/31 | integration 2/2 | data 4/4
TOTAL  150/150 public checks passing
All public checks pass. Now make sure model.npz clears the held-out test threshold, and remember the grader re-checks with DIFFERENT seeds/shapes.
All 150 public checks pass. Now let me write `train.py` and the training recipe. First, let me explore the data characteristics to design the recipe well.
shell
python3 -c "
import numpy as np
d=np.load('data/labeled.npz'); X=d['X']; y=d['y']
u=np.load('data/unlabeled.npz')['X']
print('Xl',X.shape,'yl',y.shape,'Xu',u.shape)
print('class counts', np.bincount(y))
print('X mean/std', X.mean(), X.std())
print('per-feature std (first 10)', X.std(0)[:10].round(2))
# crude: which features correlate with label? one-vs-rest mean separation
import numpy as np
C=y.max()+1
means=np.array([X[y==c].mean(0) for c in range(C)])
sep=means.std(0)  # variance of class means per feature
order=np.argsort(sep)[::-1]
print('top informative feats by class-mean spread:', order[:12])
print('their spread', sep[order[:12]].round(3))
print('median spread', np.median(sep).round(3))
"
output
Xl (200, 80) yl (200,) Xu (6000, 80)
class counts [20 20 20 20 20 20 20 20 20 20]
X mean/std -0.013586603 0.9973769
per-feature std (first 10) [0.99 1.01 1.   0.92 0.98 0.98 0.95 0.95 0.98 1.02]
top informative feats by class-mean spread: [33 28 43 57 23 19 14 24 27  9 62 48]
their spread [0.465 0.413 0.412 0.411 0.402 0.392 0.383 0.381 0.378 0.373 0.371 0.367]
median spread 0.274
All 150 public checks pass. Now let me write the FixMatch training loop in `train.py`:

/app/submission/train.py

− removed
def train(lab_path, unlab_path, out_path, steps=5000, seed=0):
    dl = np.load(lab_path)
    Xl = np.asarray(dl["X"], dtype=np.float64)
    yl = np.asarray(dl["y"], dtype=np.int64).reshape(-1)
    Xu = np.asarray(np.load(unlab_path)["X"], dtype=np.float64)
    in_dim = Xl.shape[1]
    C = int(yl.max()) + 1
    # TODO: build the model + optimizer + EMA teacher (+ distribution aligner), then run the
    # FixMatch training loop (supervised CE + masked consistency with confidence-gated, optionally
    # distribution-aligned pseudo-labels), and save_checkpoint(out_path, ema.state_dict(), cfg).
    raise NotImplementedError("train")
+ added
def _accuracy(model, X, y):
    logits = model(np.asarray(X, dtype=np.float64)).data
    pred = logits.argmax(axis=1)
    return float((pred == y).mean())


def train(lab_path, unlab_path, out_path, steps=4000, seed=0,
          Xl=None, yl=None, Xu=None, Xval=None, yval=None, verbose=True):
    if Xl is None:
        dl = np.load(lab_path)
        Xl = np.asarray(dl["X"], dtype=np.float64)
        yl = np.asarray(dl["y"], dtype=np.int64).reshape(-1)
    if Xu is None:
        Xu = np.asarray(np.load(unlab_path)["X"], dtype=np.float64)
    Xl = np.asarray(Xl, dtype=np.float64)
    yl = np.asarray(yl, dtype=np.int64).reshape(-1)
    Xu = np.asarray(Xu, dtype=np.float64)
    in_dim = Xl.shape[1]
    C = int(yl.max()) + 1
    n_lab, n_unlab = Xl.shape[0], Xu.shape[0]

    rng = np.random.default_rng(seed)
    aug = np.random.default_rng(seed + 12345)
    model = MLPClassifier(in_dim, C, d_hidden=D_HIDDEN, n_layer=N_LAYER, seed=seed)
    opt = O.Adam(model.params(), lr=2e-3, weight_decay=5e-4)
    ema = S.EMATeacher(model, decay=0.999)
    aligner = S.DistributionAligner(C, momentum=0.999)

    base_lr = 2e-3
    warmup = 200
    lam_warm = 300          # keep unlabeled weight at 0 (supervised warmup)
    lam_ramp = 1500         # then ramp lambda_u 0 -> lambda_max
    lambda_max = 1.0
    tau = 0.95
    lab_bs = 64
    unlab_bs = 256
    weak_sigma = 0.1
    strong_sigma = 0.5
    strong_mask = 0.2

    best = None
    for step in range(steps):
        lr = lr_at(step, steps, ba
…[truncated 2001 chars]

contents
The file /app/submission/train.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now let me run a validation experiment to verify FixMatch beats supervised-only. I'll split the labeled set:
shell
cd /app/submission && cat > /tmp/val_exp.py <<'EOF'
import sys, numpy as np
sys.path.insert(0,'/app/submission')
import train as TR

d=np.load('/app/data/labeled.npz'); X=d['X'].astype(np.float64); y=d['y'].astype(np.int64).reshape(-1)
Xu=np.load('/app/data/unlabeled.npz')['X'].astype(np.float64)
C=y.max()+1
# stratified split: hold out 5 per class -> 50 val, 150 train
rng=np.random.default_rng(0)
tr_idx=[]; va_idx=[]
for c in range(C):
    idx=np.where(y==c)[0]; rng.shuffle(idx)
    va_idx+=list(idx[:5]); tr_idx+=list(idx[5:])
tr_idx=np.array(tr_idx); va_idx=np.array(va_idx)
Xtr,ytr=X[tr_idx],y[tr_idx]; Xva,yva=X[va_idx],y[va_idx]
print("train",Xtr.shape,"val",Xva.shape)

# supervised-only baseline: steps with lam stays 0 -> set lam_warm huge. Hack: train with Xu but lambda always 0
# Easiest: call train but we want supervised floor. Use a separate quick supervised loop via FixMatch with steps and check.
acc=TR.train(None,None,'/tmp/val_model.npz',steps=3000,seed=1,Xl=Xtr,yl=ytr,Xu=Xu,Xval=Xva,yval=yva)
print("FIXMATCH val acc",acc)
EOF
timeout 1200 python3 /tmp/val_exp.py 2>&1 | tail -30
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
=== SyncVals verifier (local re-grade of the agent's own checkpoint) ===

COMPONENT CONFORMANCE SUITE: 197/197 cases passed  (all milestones pass: True)
FINAL METRIC: held-out worst-class top-1 = 0.6655  < threshold 0.72

REWARD = 1   (1 iff every component milestone passes AND the sealed held-out metric clears its threshold)

NOTE: the in-sandbox training in the 481MB e2b box was OOM-killed (0-byte checkpoint), so the raw
in-sandbox reward was an infrastructure artifact. This reward is from a faithful LOCAL re-train of the
agent's OWN train.py (24GB, no OOM) with its own default hyperparameters, then re-graded by the real verifier.

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_dda75f972aca4c7f. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_dda75f972aca4c7f · verifier authoritative; classifier explanatory.