(verify_accepts_iff_decompress, button-enforced)
Port of the risc0 decompress chain (identical v4 gen shape: same
instance naming, same RangeFrom+closure from_bytes extraction):
- source patch cee0e17: decompress step_2 negate-then-conditional-assign
(the documented sqrt_ratio_i rewrite); extract.sh: decompress
un-opaqued, re-extracted - the step_1/step_2 external axioms vanish
from the template, decompress is transparent.
- Proofs/DecompressSpec.lean: dalek port, instance rename
Shared0FieldElement51 -> SharedAFieldElement51.
- Proofs/FromBytesSpec.lean: the v4 closure-loader walk
(range_from_index_spec + closure_call_spec; window/telescope math
identical to dalek).
- Proofs/DecompressMain.lean: decompress_of_canonical (standard three)
+ verify_accepts_iff_decompress (corollary verbatim):
accept <=> decompress(R) = [k]*(-A) + [s]*B (as points).
check.sh: 4-tier Phase 3b; full-lift cone exactly [3 standard +
Signature + sha512_hash3 + to_bytes + Error + Error.new]. Full button
green fresh.
THE FULL POINT-LEVEL LIFT NOW HOLDS ON ALL FOUR PYRAMIDS.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Third pyramid capped. Identical shape to the risc0 fork (both are
sha2-0.10 stacks): the hash oracle is the single monomorphic
sha512_hash3(R, A, m) call, extraction runs --no-default-features.
- gen/CurveSig: extracted verify glue, definitionally welded to the
proven CurveField model (every curve and scalar call resolves to a
certified definition; only the hash and wire formats are opaque).
- Proofs/SigApexSpec.lean (unchanged from dalek): verify_loop_full with
the standard three-axiom cone, and verify_accepts_iff — the verifier
accepts IFF compress([s]B - [k]A) = R byte-for-byte.
- check.sh Phase 3b enforces the apex cone to be EXACTLY
[propext, Classical.choice, Quot.sound, ed25519.Signature,
verifying.sha512_hash3, ed25519.Signature.to_bytes,
signature.error.Error, signature.error.Error.new].
- extract.sh gains the reproducible CurveSig stanza (same recipe
verified byte-exact on the risc0 fork this session).
Full check.sh green: all standard certificates + the apex audit.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
