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Section 7.2.5, paragraph 3Staged acquisition at the output level; no internal mechanism and no 8/15 explanation are established

Informal interpretation Motivation, interpretation or scope; not a formal claim.

1 Paper text

Thus the later improvement is accounted for at the output level by learning to select moves with the correct lowest bit while retaining the already accurate upper bits. This supports staged acquisition of the restoration behaviour. It does not identify an internal representation or explain why optimisation follows this order. Nor does the plateau’s proximity to 8/158/15 establish a random-bit guessing mechanism: that baseline assumes a particular distribution and prediction rule. Internal probes, interventions and independent training runs are needed to explain the transition and test its reproducibility.

Generated from paper_jmlr.tex, lines 1131–1131.

2 Explain this

At the level of outputs, the later improvement consists of getting the lowest bit of the change right while keeping the upper bits. That supports "staged acquisition". The paper is careful about what it does not conclude:

  • it does not identify an internal representation or explain why optimisation follows this order;
  • the plateau's closeness to 8/15≈0.5338/15\approx0.533 does not establish a random-bit guessing mechanism (that number assumes a particular distribution and prediction rule);
  • probes, interventions and independent runs would be needed.

3 How this is formalised

Interpretation of empirical data. The arithmetic fact 8/158/15 (the fraction of nonzero 4-bit nim-sums with lowest bit 11) is checked (Section 7.3, paragraph 3 (arithmetic)); whether it has anything to do with the plateau is not established.

Coverage record
Paper anchorpar-learning-in-stages-the-plateau-and-subsequent-improvement-p3 (website anchor; the manuscript has no label here)
Displayed asSection 7.2.5, paragraph 3
ClaimStaged acquisition at the output level; no internal mechanism and no 8/15 explanation are established
Coverage categoryInformal interpretation
Statement sourcepaper_jmlr.tex lines 1131–1131; SHA-256 of the normalised block source 6fd5cea90e31d3d6…
Depends onSection 7.2.5, paragraph 2, Section 7.3, paragraph 3 (arithmetic)
Explanationsexplain/c-plateau-interpretation, formal/c-plateau-interpretation
Build evidencefresh isolated rebuild, audit report

4 Lean statement and source

No Lean statement corresponds to this claim. This is interpretation or motivation, not a formal mathematical claim.

Build evidence: fresh isolated rebuild of all 38 bundled modules with Lean (version 4.26.0, started 2026-10-10T15:21:56Z, finished 2026-10-10T15:27:00Z: 38/38 modules compiled, 1588 axiom reports, no errors. See Build for the commands and the independent audit of 2026-10-10 (dated evidence).