| is_obj(str, r, st), validrefs(str, r ' + refs1, mkclasstype(`java.lang.Object' .class), st) ⊦ ∃ refs0. dups(refs0) ∧ refs0 .first = r ∧ validrefs(str, refs0, st[refs0 .first -- _type] .type, st), ¬ r ∈ refs1 ∧ ¬ dups(refs1) |
⊦ ¬ validrefs(str, r ' + refs, st[r -- _type] .type, st) → ¬ validrefs(str, r ' + refs, ty, st)
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ dups(r ' + refs) ↔ dups(refs) ∨ r ∈ refs], [CSIMPSEQ : ⊦ (refs + refs0) + refs1 = refs + refs0 + refs1], [CSIMPSEQ : ⊦ (r ' + refs) .first = r])], [EXTRATERMS : (r ' + refs1)]]