Pith. sign in

REVIEW 10 cited by

Learning Compositional Functions with Transformers from Easy-to-Hard Data

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2505.23683 v1 pith:EKHB24BR submitted 2025-05-29 cs.LG

Learning Compositional Functions with Transformers from Easy-to-Hard Data

classification cs.LG
keywords datacompositiondistributionfoldlearningtaskstransformerswork
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
Share X Bluesky LinkedIn Reddit HN
read the original abstract

Transformer-based language models have demonstrated impressive capabilities across a range of complex reasoning tasks. Prior theoretical work exploring the expressive power of transformers has shown that they can efficiently perform multi-step reasoning tasks involving parallelizable computations. However, the learnability of such constructions, particularly the conditions on the data distribution that enable efficient learning via gradient-based optimization, remains an open question. Towards answering this question, in this work we study the learnability of the $k$-fold composition task, which requires computing an interleaved composition of $k$ input permutations and $k$ hidden permutations, and can be expressed by a transformer with $O(\log k)$ layers. On the negative front, we prove a Statistical Query (SQ) lower bound showing that any SQ learner that makes only polynomially-many queries to an SQ oracle for the $k$-fold composition task distribution must have sample size exponential in $k$, thus establishing a statistical-computational gap. On the other hand, we show that this function class can be efficiently learned, with runtime and sample complexity polynomial in $k$, by gradient descent on an $O(\log k)$-depth transformer via two different curriculum learning strategies: one in which data consists of $k'$-fold composition functions with $k' \le k$ presented in increasing difficulty, and another in which all such data is presented simultaneously. Our work sheds light on the necessity and sufficiency of having both easy and hard examples in the data distribution for transformers to learn complex compositional tasks.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 10 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Transformers Provably Learn to Internalize Chain-of-Thought

    cs.LG 2026-05 unverdicted novelty 8.0

    L-layer transformers under Log-ICoT curriculum provably learn k-parity with poly(n) samples and log k stages, matching explicit CoT efficiency without inference overhead.

  2. Transformers Efficiently Perform In-Context Logistic Regression via Normalized Gradient Descent

    cs.LG 2026-05 conditional novelty 7.0

    Multi-layer transformers can implement in-context logistic regression by performing normalized gradient descent steps layer by layer, obtained via supervised training of a single attention layer followed by recurrent ...

  3. Sharp Capacity Scaling of Spectral Optimizers in Learning Associative Memory

    cs.LG 2026-03 unverdicted novelty 7.0

    Muon achieves higher storage capacity than SGD and matches Newton's method in one-step recovery rates for associative memory under power-law distributions, while saturating at larger critical batch sizes and showing f...

  4. Scaling Latent Reasoning via Looped Language Models

    cs.CL 2025-10 unverdicted novelty 7.0

    Looped language models with latent iterative computation and entropy-regularized depth allocation achieve performance matching up to 12B standard LLMs through superior knowledge manipulation.

  5. The Power of Power Law: Asymmetry Enables Compositional Reasoning

    cs.AI 2026-04 unverdicted novelty 6.0

    Power-law data sampling creates beneficial asymmetry in the loss landscape that lets models acquire high-frequency skill compositions first, enabling more efficient learning of rare long-tail skills than uniform distr...

  6. The Power of Power Law: Asymmetry Enables Compositional Reasoning

    cs.AI 2026-04 unverdicted novelty 6.0

    Power-law data distributions outperform uniform ones for compositional reasoning by creating asymmetry that lets frequent skill compositions scaffold rare ones with less data.

  7. Breaking the Reversal Curse in Autoregressive Language Models via Identity Bridge

    cs.AI 2026-02 conditional novelty 6.0

    Identity-bridge regularization, rephrased into an out-of-context reasoning form, yields ~40% reversal accuracy in a 1B LLM and provably fixes reversal in an idealized one-layer transformer.

  8. Transformers with RL or SFT Provably Learn Sparse Boolean Functions, But Differently

    cs.LG 2025-11 conditional novelty 6.0

    Under hand-designed masks and task-specific activations, RL fine-tuning learns a k-sparse Boolean reasoning chain in one gradient update while SFT learns it one CoT step per update.

  9. Deep sequence models tend to memorize geometrically; it is unclear why

    cs.LG 2025-10 unverdicted novelty 6.0

    Deep sequence models develop geometric memory in embeddings that encodes novel global relationships, transforming l-fold composition tasks into 1-step navigation via a natural spectral bias connected to Node2Vec.

  10. Scaling Latent Reasoning via Looped Language Models

    cs.CL 2025-10 conditional novelty 5.0

    A 1.4B and a 2.6B looped (weight-tied, recurrent-depth) language model trained on 7.7T tokens match or exceed several 4B–8B transformer baselines on selected reasoning benchmarks.