maude: Phase 3 — equational matching modulo assoc/comm/id (28 tests, 119 total)

The chisel. lib/maude/matching.sx: multi-valued matcher mau/mm returning
ALL substitutions, dispatching on op theory (free/comm/assoc/AC). Identity
lets variables grab empty blocks. AC-canonical form (mau/canon) powers
ac-equal? and deterministic printout. AC rewriting extends f-AC equations
with rest vars so a rule fires on any sub-multiset/subword; mau/first-change
only commits rewrites that change the canonical form (idempotency/identity
terminate). Verified on multiset rewriting, set theory, group equations.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/maude/scoreboard.json

@@ -1,11 +1,12 @@
 {
   "lang": "maude",
-  "total_passed": 91,
+  "total_passed": 119,
   "total_failed": 0,
-  "total": 91,
+  "total": 119,
   "suites": [
     {"name":"parse","passed":65,"failed":0,"total":65},
-    {"name":"reduce","passed":26,"failed":0,"total":26}
+    {"name":"reduce","passed":26,"failed":0,"total":26},
+    {"name":"matching","passed":28,"failed":0,"total":28}
   ],
-  "generated": "2026-06-07T14:45:37+00:00"
+  "generated": "2026-06-07T15:00:34+00:00"
 }