ABI Layer 4: prove the FFI result-code seam is injective + faithful#48
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New module K9iser.ABI.Semantics proves the repo's headline property
("Wrap configs into self-validating K9 contracts"): a config that
SATISFIES a "must"-contract (a required key present whose value lies
within an inclusive numeric range) provably validates, and a config that
VIOLATES it (missing key OR out-of-range value) provably does not.
- Faithful model: Config = assoc list (Key, Nat); Contract = key + [lo,hi].
- Headline proposition `Validates c cfg` has constructors only for the
satisfying case (resolver equation + InRange via propositional LTE);
no constructor exists for a missing key or out-of-range value.
- Sound + complete `decValidates : Dec (Validates c cfg)` and `decInRange`.
- Certifier `certify` into the ABI Result code, with `certifySound` and
`certifyComplete`.
- Positive control `goodValidates` (replicas=5 in [1,10]) and two negative
controls: `badRangeNotValidates` (replicas=0) and `missingNotValidates`.
ABI builds clean (exit 0, zero warnings). A deliberately false witness
for the out-of-range config is rejected by idris2 (non-vacuity verified).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A6PSzJWpRxtzGDjUCEh7Mx
Add a second, deeper machine-checked theorem over the existing Layer-2
Semantics model, raising the Idris2 ABI to Layer 3. Proves how config
validation behaves under CONJUNCTION of K9 contracts, distinct from the
Layer-2 single-contract soundness/completeness:
- ValidatesBoth / ValidatesAll: binary and n-ary conjunction over the
existing Validates proposition.
- validatesAndIff / validatesAllConsIff: decomposition isomorphisms
(real witness round-trips, = Refl).
- validatesBothSym: commutativity of conjunction.
- decValidatesAll: sound + complete decision, built compositionally
from the Layer-2 decValidates.
- validatesAllAppend{Fwd,Bwd}: distribution of conjunction over list
append (induction on the bundle).
- validatesAllWeaken: monotonicity / downward-closure.
- certifyAll{,Sound,Complete}: certifier into the ABI Result code.
- Positive controls (twoValidatesBoth / twoValidatesBundle) and
negative / non-vacuity controls (mixedNotBoth / mixedNotBundle),
all machine-checked; resolver equations proved via resolveHead /
resolveSkip lemmas (String decEq does not reduce definitionally).
No believe_me / postulate / assert_total / sorry. %default total.
Registered last in k9iser-abi.ipkg. Clean build, zero warnings;
a deliberately-false ValidatesAll over the out-of-range config is
rejected by the type checker (non-vacuity confirmed).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A6PSzJWpRxtzGDjUCEh7Mx
Prove resultToInt is a sound wire encoding: a faithful decoder intToResult with resultRoundTrip (lossless), injectivity derived from the round-trip, positive decode controls, and a machine-checked non-vacuity control (distinct codes have distinct ints). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01A6PSzJWpRxtzGDjUCEh7Mx
Signed-off-by: Jonathan D.A. Jewell <6759885+hyperpolymath@users.noreply.github.com>
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Summary
Layer 4 (seal the ABI↔FFI seam): proves the FFI result-code encoding (
resultToInt) is a sound, lossless wire encoding — decoderintToResultwithresultRoundTrip, from whichresultToIntInjectiveis derived. Distinct ABI outcomes never collide on the C wire. Complements the structuralabi-ffi-gate.py.New module
*.ABI.FfiSeam(importsTypes). Positive + non-vacuity controls.Testing
Idris2 0.7.0
--build→ exit 0, zero warnings. Adversarial rejection confirmed.build/removed. Nobelieve_me/postulate/sorry.🤖 Generated with Claude Code
https://claude.ai/code/session_01A6PSzJWpRxtzGDjUCEh7Mx
Generated by Claude Code