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If true, Theorem 5.5 + Lemma 5.3 → Conjecture 5.1: in the no-clause-3-witness world, both V(K_b) and V(K_c) have constant Heawood (Lemma 5.3), but K_b and K_c share the merged edge, contradicting Theorem 5.5. Proof sketch sets up the two Lemma-5.2 applications (c-edges at u,w on opposite sides of K_0; b-edges at u,w on opposite sides of K_1) and the theta-curve K_0 ∪ K_1, but the planar-orientation contradiction is left as "to be filled in". Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>