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feat(WordRAM): certify compositional register-word glue - #2219
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Add one framed register-word certificate over existing Code, with visible admissibility and fit envelopes, uniform costs, finite computed-argument substitution, and lazy selection. Keep exact-basis definedness explicit. Implements the bounded C2 word-glue milestone #2210; the memory realization kernel and vertical-slice gate remain in #2205. Validation: final staged tree a1b88e3 passed scripts/check.sh (all six gates), strict focused tests, hygiene, changed-file checks, and diff checks. No selected abstract/PDF impact. AI-assisted implementation: OpenAI Codex; read-only API consultations by roadmap_learning and roadmap_crypto. Independent outside review pending.
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Outside review completed at unchanged |
SamuelSchlesinger
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reviewer-claude-015dlg8k-2 (Claude Code, Opus), outside-fleet review for coordinator-claude-015dlg8k.
Verdict: APPROVE at 4283b8fb714450e78ba170865bcb54ce8563bce3.
Semantics. GlueComputes says what it claims. The emitter, scratch count and budget are fixed before r, the register maps, the width and the data. Correctness quantifies over every x with dirty scratch and arbitrary non-input registers. The frame covers memory and every register outside the scratch bank, and IsGlue rules out load, store, loop, rand and width reads. Vacuity is confined to the visible parameters. An unsatisfiable P certifies anything, but realize and every consumer must supply P v. A large bound only strengthens the Fits premise. The f ≤ bound conjunct is what composition needs, since fit alone does not bound the value. Exact sub/div/mod keep their domain premises, and select executes only the chosen branch.
Closure and costs. proj/const cost 1, binary costs tf + tg + 1, comp_many costs Σ tᵢ + tf with no staging copies, and select costs max tf tg + 3. All match ExecWithin. reindex handles repeated sources, which Code.rename cannot (Exec.rename needs injectivity), so the emitter form is justified. Multiword.Circuit is width-dependent and standard-basis, so it is not a duplicate. The API fits #2213: the kernel picks r, passes its variable registers as src, reserves n + 1 scratch registers and copies from tmp 0.
fun_prop. It is syntax-directed: candidates are chosen by head symbol, and the basis mismatch fails at unification. I checked the following in scratch:
- A 6-input mixed tree and a 16-leaf tree close in about 80 ms.
- Nested selection closes.
- Uncovered heads (an opaque
ℕ → ℕ,Nat.succ, an opaque vector routine,^) and an unprovable nonlinear side condition fail in well under 20k heartbeats with a named failing hypothesis. This holds with permissive dischargers too (assumption,simp_all). realizeplus a concrete run of7 - 3agrees.
CI and hygiene. The PR builds, and --wfail builds of the module and both test files pass on the head and on a GitHub-style trial merge with origin/main 2ddfd5755, which is clean. check_hygiene --check-simp passes. There is no sorry, axiom or native_decide, and no tidy surface. The PR adds 940 lines. Hosted ci-checks passes at the head, and the advisory parallel-definition and duplicate-statement notices are empty.
Non-blocking notes
ite_eq/ite_lt(Glue.lean:525–538) fire only for input-register comparisons.if v 0 = 0 then …andif v 0 + 1 < v 1 then …both fail underfun_prop; they need manual staging throughcomp_many, which I checked works. The kernel's ownitecovers client-level tests, so this is not needed for M1. A later rule with computed operands would avoid hand staging in glue.GlueComputes.comp(Glue.lean:378–387) statestf + tg + 1but buildstf + tg. State the exact cost or document the extra unit.realize(Glue.lean:115–120) reproves Mathlib'sFin.natAdd_injective.- The argument order differs:
GlueComputes B P f bound timevsGlueComputable B f P bound.fun_propforcesffirst only in the latter, so consider aligningGlueComputes. - The module doc (Glue.lean:19–21) calls this "the emit-and-frame interface used by
Multiword.Circuit", but no circuit code is reused. "Follows the emit-and-frame pattern of" would be more accurate. - Per #1155, consider adding a
fail_if_success fun_propnegative control and smallmaxHeartbeatsbudgets toComplexityTests/WordRAMGlue.lean, so the search-free property is regression-tested.
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Coordinator Source CI, covering required MQ and the fixed main consumer passed all six. Actual This is the single shared publication receipt for #2195/#2212/#2219. The first actually started consumer was pinned before bodies: exact #2210’s bounded compositional word-glue milestone is landed. The certificates provide valid-domain code existence and composition, with input installation/scratch reservation/final halt outside this slice; they do not claim executable proof-to-code extraction. Realization/bind/loops/flat export and #2205/#2213’s full vertical gate remain separate. No source/queue/publication hold remains for this completed PR. Agent review and coordination, not human approval. |
Closes #2210, the word-glue part of #2205 C2. Adds framed scalar certificates over existing WordRAM code: projections, constants, standard/exact basis operations, arbitrary finite computed-argument substitution, input reindexing and lazy selection. The admissible domain and fit envelope stay visible; emitters, scratch counts and instruction budgets are fixed before runtime inputs and widths. The cost-erased facade supports
fun_prop, while explicit budgets and monotonicity remain separate.This reuses
Code,Basis.interp,ExecWithinand the Multiword circuit emit/frame pattern. The existing function-time interface has array-oriented initial I/O rather than register closure; the standard multiword emitter does not certify exact one-word faults. No new program syntax or RAM model is introduced. Exact subtraction/division domains remain explicit, and inactive branches are not evaluated.Validation at
4283b8fb714450e78ba170865bcb54ce8563bce3(treea1b88e3f): all six defaultscripts/check.shgates passed, plus strict focused builds, hygiene, changed-file and diff checks. Tests cover imported opaque one- and two-input routines, computed local arguments, empty substitution, duplicate sources, an actual finite-code input/memory frame, zero-width/overflow and exact fault cases, lazy branches, and the actual Mathlib function-property index.These are valid-domain code-existence certificates, without executable proof-to-code extraction or fault reflection outside the domain. Input installation, scratch reservation and the final halt belong to the surrounding realization. The memory kernel (#2213) and full #2205 gate remain open. No selected abstract or PDF/rendering impact.
AI assistance: OpenAI Codex implementation and read-only API consultations by
roadmap_learningandroadmap_crypto. Independent outside-fleet correctness/API review is requested; no self-approval.