swaitsandClaude Opus 4.7
7004a572c8
ERX had five tests, all checking `is_strict_perm` validity -- none verified the *point* of edge recombination: that children actually inherit parent edges. A "valid permutation but edge-ignoring" ERX would have passed every existing test. Adds: - erx_identical_parents_inherit_every_edge: with identical parents the child's edge set must equal the parent's exactly (zero foreign edges). - erx_preserves_parent_edges_better_than_order_crossover: ERX must strand fewer non-parent edges than Order Crossover -- a direct test of ERX's reason to exist. - erx_pinned_output: locks the adjacency-walk + min-degree tie-break. Investigation result: ERX is correct and effective. It wins the tsp_operators_compare showdown on KroAB-25 (hypervolume 638M vs OX 622M, PMX 609M, CX 593M) and produces the most diverse front. The compare TSP table's GA underperformance is an Order-Crossover-plus-generational-GA artifact on a convex-position instance, not an ERX bug. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>