test_proof_chain_rules.py carried a 24-case inline copy of the same modus_ponens
contract oracle #529 committed as tests/fixtures/proof_chain/modus_ponens_cases.json.
Load the fixture instead — it is now the single source of truth. Its expected.reason
is already the ADR-0205 closed set (closed_reasons == MP_REASONS), so this is a pure
de-dup: the loaded cases were verified byte-for-byte against the prior inline table
(24/24, 0 diffs). The pooling tests (DISAGREE-007/010/003) now pull premises from the
oracle by id too, so no case is re-transcribed anywhere. Added a contract guard
(24 cases; reasons subset of MP_REASONS; closed_reasons == MP_REASONS); dropped the
now-unused closed-reason imports.
Phase 2.3: the first inference rule + the wrong=0 mechanism for proofs.
- generate/proof_chain/rules.py: evaluate_modus_ponens / evaluate_proof_conclusion.
Proof-layer dispatch (Option B) over proposition FORMULAS via the canonicalizer;
never touches check_admissibility/_resolve_dep_units (proofs have no units).
Disagreement rule = the select_self_verified twin: pool ALL admissible single-step
MP derivations, require a unique canonical key == declared conclusion. Pooling (not
filter-to-declared-first) is the soundness mechanism.
- generate/logic_canonical.py: parse_top_implication (+ _unparse) — recovers an
implication's syntactic antecedent/consequent (the ROBDD form doesn't preserve it).
- Closed typed-reason set; the corpus's finer labels consolidate (6 disagreement
refuse-labels -> conclusion_disagreement; 4 antecedent-flavor labels ->
unestablished_antecedent — same redundancy, same mechanism-makes-one-distinction
principle).
- Honesty boundary (exact scope): guarantees a unique conclusion among SINGLE-STEP MP
over the premises, NOT "uniquely entailed" by all strategies.
Cross-check: all 24 GPT-5.5 adversarial corpus cases agree on OUTCOME against the real
rule (no rule bug / no corpus outcome-misread); reasons consolidate as above.
Mutation: filter-to-declared-first makes DISAGREE-007/010 wrongly admit -> pooling
tests fail (pooling load-bearing).
Drive-by fix (cleanup-as-you-find): merged ADR-0204 ProofNode.__post_init__ was
dedented to module level -> all ProofNode validation was silently DEAD (smoke skips
the dedicated test file; the smoke != full-suite hazard). Re-indented; validation
restored.
Additive (math lane untouched). Full binding-graph surface green; smoke 67.