Prove split lengths and non-overlapping numerical regions

[joshlf]

Use the proved length and zero-padding helpers in the existing split path.
An ordinary Rust assertion root compares sizes with the independent
remainder-based reference and checks physical tail containment.
Prove bounds and disjoint numerical intervals, including empty and
zero-sized tails. Pointer validity and provenance remain Rust obligations.

Validation: pinned extraction; independent golden/live proofs,
required-contract checks and axiom audits; targeted Rust tests.

Agent-authored-by: AI agent acting on joshlf's behalf

---

• 　  Prove record construction against independent Rust references #3744
• 　  Prove cast metadata composition against reference sizes #3777
• 　  Prove numerical cast plan selection and metadata conversion #3776
• 　  Prove cast validation and exact metadata inference #3755
• 　  Prove allocation size preparation and tail containment #3790
• 　  Prove the concrete CastUnsized layout gate #3789
• 👉 Prove split lengths and non-overlapping numerical regions #3788
• 　  Prove byte advancement and padding sequence queries #3754
• 　  Prove normalized layout padding and field extension #3753
• 　  Prove concrete pointer metadata operations #3787
• 　  Prove exact trailing sizes, padding and capacity #3752
• 　  Prove primitive layout constructors with recursive mathematical models #3751
• 　  Compare nested DST sizes with a recursive Rust oracle #3749
• 　  Model alignment and phase encoding as a bounded mathematical pair #3747
• 　  Refine recursive record semantics into normalized layouts #3743
• 　  Prove trailing-layout normalization and capacity arithmetic #3742
• 　  Reuse Aeneas specifications for views and indexed loops #3745
• 　  Strengthen arithmetic specifications and prove arithmetic corollaries #3746
• 　  Check native total and partial Aeneas specifications #3739
• 　  Prove unsigned byte-order reads, writes and updates #3800
• 　  Verify doc-owned specifications over recursive mathematical models #3738
• 　  Separate numerical cast planning from typed pointer projection #3774
• 　  Move pointer cast implementation into its own source file #3773
• 　  Share Rust mathematical models across Anneal frontends #3799

Latest Update: v4 — Compare vs v3

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Links show the diff between the row version and the column version.

Version	v3	v2	v1	Base
v4	vs v3	vs v2	vs v1	vs Base
v3		vs v2	vs v1	vs Base
v2			vs v1	vs Base
v1				vs Base

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[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-06T00:34:45.019007Z	4d1e8e4	PR opened
🔒 Security Review	✅ Completed 2026-10-06T00:35:54.470832Z	4d1e8e4	PR opened

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Codecov Report

❌ Patch coverage is 12.12121% with 58 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (G5ef3gjdnvnuoek33bzy6bovxsxprq4wm@75e86ca). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
zerocopy/src/split_at.rs	11.29%	55 Missing ⚠️
zerocopy/src/layout/tail_checks.rs	0.00%	2 Missing ⚠️
zerocopy/src/layout/tail_transform_checks.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@                         Coverage Diff                          @@
##             G5ef3gjdnvnuoek33bzy6bovxsxprq4wm    #3788   +/-   ##
====================================================================
  Coverage                                     ?   54.32%           
====================================================================
  Files                                        ?       26           
  Lines                                        ?     4210           
  Branches                                     ?        0           
====================================================================
  Hits                                         ?     2287           
  Misses                                       ?     1923           
  Partials                                     ?        0           

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