| path∃(str, r, r0, st), unchanged(str, r, st, st0) ⊦ unchangedNorec(r0, st, st0) |
⊦ unchanged(str, r, st, st0) ↔ (∀ r0. (path∃(str, r, r0, st) ↔ path∃(str, r, r0, st0)) ∧ (path∃(str, r, r0, st) → unchangedNorec(r0, st, st0)))
path∃(str, r, r0, st), ∀ r0. (path∃(str, r, r0, st) ↔ path∃(str, r, r0, st0)) ∧ (path∃(str, r, r0, st) → unchangedNorec(r0, st, st0)) ⊦ unchangedNorec(r0, st, st0)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st0, st, r, str)]]