DETERMINE was one-hop. C answers a member/subset query that holds by SOUND transitive
subsumption when direct entailment misses: member∘subset* and subset∘subset (the
Description-Logic is-a rules). 'Socrates is a man. All men are mortal. Is Socrates
mortal?' -> yes, as told.
wrong=0 hazard surfaced and closed: member∘member is NOT transitive (instance-of vs
subclass-of) — 'Socrates is a man. Man is a species.' does NOT entail 'Socrates is a
species'. That rule is NEVER an edge, so the fallacy is unreachable (bite-tested). The
reader's member/subset split (X is a Y vs all Xs are Ys) is exactly the instance-of/
subclass-of distinction that makes the included rules sound.
Mechanism: SEARCH-then-VERIFY. Reachability over the sound edges finds the chain, then
the proof_chain ROBDD verifies that chain's propositional entailment (O(path) premises).
Full O(n³) grounding into proof_chain was tried and rejected: it overruns the
canonicalizer's per-conjunct recursion, and transitive closure is reachability, not
general SAT. Search-then-verify scales (11-hop chain determines in ~2ms) and keeps the
sound+complete decider as the wrong=0 verifier + proof artifact.
subset is now a supported direct-entailment predicate (a told subset(a,b) answers it);
the other categoricals (disjoint/intersects/some_not) stay excluded. Two existing tests
updated accordingly (subset->ungrounded, disjoint stays unsupported_query).
