| validrefs(str, r ' + refs1 + r0 ', st[r -- _type] .type, st[r0 -- sk, val]) ⊦ sk = _type, r = r0, r ∈ refs1, dups(refs1), r0 ∈ refs1, junkref(str, r, st), validrefs(str, r ' + refs1 + r0 ', st[r -- _type] .type, st) |
⊦ ¬ validrefs(str, refs + r0 ', ty, st) ∧ ¬ junkref(str, refs .first, st) ∧ refs ≠ [] ∧ ¬ r0 ∈ refs ∧ sk ≠ _type → ¬ validrefs(str, refs + r0 ', ty, st[r0 -- sk, val])
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ (r ' + refs) .first = r], [CSIMPSEQ : ⊦ ¬ refs + refs0 ≠ [] ↔ refs = [] ∧ refs0 = []], [CSIMPSEQ : ⊦ r ' ≠ []], [CSIMPSEQ : ⊦ r ≠ r0 → (r ∈ r0 ' + refs ↔ r ∈ refs)], [CSIMPSEQ : ⊦ (refs + refs0) + refs1 = refs + refs0 + refs1])], [EXTRATERMS : (val, sk, st, st[r -- _type] .type, r0, r ' + refs1, str)]]