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Writing study: Softmax Transformers are Turing-Complete

← ICLR 2026 oral writing corpus

Hongjian Jiang, Michael Hahn, Georg Zetzsche, Anthony W. Lin · Official ICLR 2026 oral record

Figure, table and section ledger

Editorial contribution type: Theory & formal foundations (primary).

Layout extraction, not a required paper template. Counts are distinct caption labels; a multi-panel figure counts once. Section spans are estimated from heading positions, including floats and whitespace. Method and limitations.

Canonical PDF
21 physical pages
Before references / appendix
≈ 10.21 page-equivalents
Main figures / tables
1 / 1
Attached appendix figures / tables
0 / 2
Attached appendix span
≈ 7.62 page-equivalents
Before references / appendix: ≈ 48.62%References / intervening material: ≈ 15.1%Attached appendix: ≈ 36.29%Estimated layout envelopes, not text/artwork area. Unresolved appendix boundaries remain within the undivided post-body material.
Section-by-section lengths and source pages

The title/abstract/front matter precede the first numbered heading. A span ends at the next detected top-level heading, not at the last sentence; end-page whitespace is included. References and statements are listed separately. These are not measurements of text-only or artwork area.

Top-level headingStarts on PDF pageEstimated spanShare of entire PDF
1 INTRODUCTION1≈ 1.13 pp.5.38%
2 MODELS FOR TRAINABLE COT TRANSFORMERS2≈ 2.84 pp.13.52%
3 UNARY CASE5≈ 2.18 pp.10.38%
4 GENERAL CASE7≈ 2.44 pp.11.62%
5 EMPIRICAL EXPERIMENTS10≈ 0.49 pp.2.33%
6 CONCLUDING REMARKS10≈ 0.51 pp.2.43%
ACKNOWLEDGMENTS11≈ 0.1 pp.0.48%
REFERENCES11≈ 3.17 pp.15.1%
A ADDITIONAL MATERIAL ON SECTION 214≈ 3.47 pp.16.52%
B ADDITIONAL MATERIAL ON SECTION 317≈ 0.4 pp.1.9%
C ADDITIONAL MATERIAL ON SECTION 418≈ 1.04 pp.4.95%
D ADDITIONAL MATERIAL ON SECTION 519≈ 2.72 pp.12.95%
All detected figure and table locations

Argument and organization

  1. Definitions and staged expressivity results

    Builds the theorem through unary, letter-bounded and permutation-invariant cases before general languages.

  2. Construction, experiments and technical appendices

    Separates constructive proof from finite-length supporting experiments and places formal details in section-matched appendices.

Problem, claim and contribution

The introduction contrasts soft attention with earlier hard-attention constructions, then states the additional chain-of-thought and positional assumptions rather than presenting a generic capability benchmark.

Sections 1–2, pp. 1–4 · Main paper

Argument and section order

The progression from counting-friendly languages to arbitrary languages makes the necessity of the encoding phase intelligible; phase I stores an input encoding and phase II simulates a counter machine.

Sections 3–4, pp. 5–9 · Main paper

Figures, captions and visual explanation

A small two-state counter-machine diagram supplies an example repeatedly reused in the construction. Its transition labels match the surrounding equations, although the dense wrapped text leaves little explanatory caption space.

Figure 1 and Example 1, pp. 6–7 · Main paper

Tables, comparisons and evidence

Table 1 groups columns first by representation/position encoding and then by three length splits, so the generalization contrast can be read horizontally without separate plots.

Section 5, Table 1, p. 10 · Main paper

Appendix and reproducibility

The section-matched appendices distinguish formal architectural assumptions from the actual ReLU training implementation and document whole-trace exact match rather than merely answer accuracy.

Appendices A.1–A.4 and D.1–D.2, pp. 14–17, 19–21 · Main paper

Clarity and writing conventions

The headline needs explicit qualification: the proof uses log-length attention scaling, threshold activations and an idealized learner; the learned finite-length experiments do not establish a practical universal-computation guarantee.

Appendices A.1–A.4 and Section 5 · Main paper

What to reuse—and what not to infer

Transferable lesson: For a theoretical paper, organize intermediate cases around the obstacle each removes, reuse one concrete running example, and distinguish theorem assumptions from experimental implementations.

Boundary: Turing completeness permits unbounded computation; the result is not a guarantee for ordinary finite-precision LLMs, SGD or standard RoPE. Table 3 uses different model sizes across encoding conditions, and the main early-stopping description refers to test0, warranting protocol clarification.

Apply this lesson using the argument and evidence worksheet.

Inspection record and sources

Checked
2026-09-19
Reading status
Full text + selected visuals inspected
Main text
Pages 1–10, Sections 1–6; definitions, NoPE construction, general RPE construction and experiments.
Appendix / supplement
Pages 14–21, Appendices A–D, including formal SMAT definition, proofs, learning framework and experimental data/setup.
Visually inspected PDF pages
6, 10