rivet: reframe FEAT-057 slice-2 (straight-line poly is vacuous over wrapping ints) - #106
Merged
Conversation
…wrapping ints Records the 2026-07-14 discovery: the intended additive straight-line polyhedra pass (mirroring the bits/float passes) is near-vacuous for a SOUND reason. Over Wasm's wrapping i32, a general-coefficient fact (z = x+y) is unsound unless no-wrap is proven, which needs bounds → guards → the fixpoint. So the poly body requires the full fixpoint integration (Poly on FuncCtx in lockstep with the octagon, wrap-aware transfers, guards, Poly::project) — a multi-slice arc, not a straight-line shortcut. Slice-1 (the crate) shipped in 3.2.1; this honestly re-scopes slice-2. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
📐 rivet artifact deltaPR: #106 Base SHA: Validationhead — `rivet validate` resultbase — `rivet validate` result (for comparison)Artifact stats
full stats — headDiff (base → head)AADL model — headPosted by the |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Artifact-only. Records a soundness discovery from wiring FEAT-057 slice-2.
Discovery: the intended additive straight-line polyhedra pass (mirroring the bits/float passes) is near-vacuous, and for a sound reason. Polyhedra's value is general-coefficient facts (
z = x + y), but over Wasm's wrapping i32 that equality is unsound unless no-wrap is proven — which needs value bounds → guards → the fixpoint. On straight-line code with unbounded params, every arithmetic result may wrap, so no octagon-beating fact is soundly emittable. (Unlike bits/float, which are wrap-internal.)Consequence: the polyhedra body requires the full fixpoint integration — a
PolyonFuncCtxthreaded in lockstep with the octagon, wrap-aware assignment transfers gated on the interval no-wrap result, guard refinement, andPoly::project(FM elimination). A multi-slice arc like the octagon's v1.7–1.9, tracked honestly rather than crammed.slice-1 (the
scry-sai-polycrate) shipped in 3.2.1; this re-scopes slice-2.rivet validatePASS.🤖 Generated with Claude Code