core chat now decides Aristotelian syllogisms end-to-end -- the marquee
'basic logical work' widening. Closes Phase 0's fork: the ONLY categorical
decider was evals/syllogism/oracle.py (the sealed independence oracle serving
must not import; INV-25). This ships a production decider.
generate/proof_chain/categorical.py lowers a categorical argument to the
propositional regime (one Boolean atom per term-membership profile) and rides
the already-verified ROBDD engine -- no new decision procedure, soundness
inherits from the flagship. Sound AND complete for the modern/Boolean reading
(Darapti + existential-import-only forms correctly INVALID), with no reliance
on a lucky domain size. Independent of the eval oracle by mechanism (ROBDD-
over-profiles vs brute-force finite-model enumeration); proven by case-for-case
agreement with it across the whole syllogism gold lane.
New: generate/proof_chain/categorical.py, render_syllogism (deterministic
valid/invalid/inconsistent templates), CATEGORICAL shape-band, arena
categorical band (4 valid forms + 2 invalid, by-construction gold cross-checked
vs the independent syllogism oracle), tests/test_categorical_decider.py (8
tests incl. the independence-by-agreement proof).
Changed: chat/deduction_surface.py (categorical branch, license-gated via a
shared _license_gate helper; propositional path byte-identical), arena
DeductionSolver dual-path in lock-step with the composer, re-sealed ledger (5
bands, categorical earns SERVE at 0.99087 wrong=0), Phase-2 lane decide()
mirrors the dual path with the 3 categorical cases reclassified to their true
valid/invalid verdicts + 1 invalid case (n 27->28), report+SHA regenerated.
Honest wrinkles: irregular plurals ('fish') decline with unknown_morphology
(a reader limit, correctly not a wrong); surfaces read in singularized terms
('all whale are animal') -- the exact ids the engine reasoned over, no cosmetic
re-pluralization that could drift from the decision.
[Verification]: smoke 180 passed; cognition 122 passed/1 skipped; core test
--suite deductive 45 passed; test_categorical_decider 8 passed; practice
runner 5 bands all SERVE wrong=0; deduction_serve lane SHA regenerates to the
committed pin.
New evals/deduction_serve/ lane scores the PRODUCTION serving decider
(the exact comprehend -> to_deductive_logic -> evaluate_entailment_with_trace
pipeline chat/deduction_surface.py runs) end-to-end from raw text --
distinct from evals/deductive_logic (bare engine vs formula strings) and
evals/comprehension/propositional_runner.py (reader fidelity vs the
independent oracle, not the production engine). This is the only lane
proving the capability core chat actually serves.
27 hand-authored cases (gold computed by independent logical reasoning,
not copied from a first engine run), 4 classes: entailed/refuted/unknown/
declined. 27/27 correct, wrong=0. Wired into core test --suite deductive
(tests/test_deduction_serve_lane.py) and SHA-pinned in
scripts/verify_lane_shas.py (deduction_serve_v1).
Honesty check during authoring: a case intended as 'entailed'
(contraposition, 'Therefore if not q then not p') actually declined --
tracing why found a genuine reader-grammar boundary (negation cannot
nest inside an if/then clause; generate/meaning_graph/reader.py's _chunk
rejects it). Reclassified to declined/out_of_band_nested_negation
(documented in contract.md) rather than forcing an artificial pass, and
added a replacement entailed case (three-hop chain) to keep coverage.
Out-of-scope finding (documented, not fixed here): running
scripts/verify_lane_shas.py --update to compute this lane's pin also
re-executed every OTHER registered lane and surfaced two pre-existing,
unrelated problems on main -- miner_loop_closure/curriculum_loop_closure/
demo_composition regenerate non-deterministic content IDs (their
committed pins don't reproduce even on a clean checkout), and public_demo
errors outright (matches the known env-timeout flake in project memory).
Reverted all four lanes' results/*.json and PINNED_SHAS entries to their
original committed values -- this PR's only PINNED_SHAS change is the new
deduction_serve_v1 entry.
[Verification]: smoke 180 passed; cognition 122 passed/1 skipped;
core test --suite deductive 25 passed; evals.deduction_serve.runner
27/27 wrong=0; pinned SHA independently re-verified against the
committed report.json bytes.
