| validrefs(str, refs, ty, st0), r ∈ refs, ∀ r. r ∈ refs → unchangedNorec(r, st, st0) ⊦ validrefs(str, refs, ty, st), unchangedNorec(r, st0, st) |
⊦ unchangedNorec(r, st, st0) ↔ unchangedNorec(r, st0, st)
validrefs(str, refs, ty, st0), r ∈ refs, ∀ r. r ∈ refs → unchangedNorec(r, st, st0) ⊦ validrefs(str, refs, ty, st), unchangedNorec(r, st, st0)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st, st0, r)]]