| ¬ validrefs(str, (r ' + refs) .last ' + r0 ', st[((r ' + refs) .last ' + r0 ') .first -- _type] .type, st) ∧ (r ' + refs) .last ' + r0 ' ≠ [] → ¬ validrefs(str, (r ' + refs) .butlast + (r ' + refs) .last ' + r0 ', mkclasstype(`java.lang.Object' .class), st), validrefs(str, r ' + refs, mkclasstype(`java.lang.Object' .class), st), validrefs(str, r ' + refs + r0 ', mkclasstype(`java.lang.Object' .class), st), is_valid_ref(str, r, st) ⊦ r = r0, r = jvmref, step∃(str, (r ' + refs) .last, r0, st) |
validrefs(str, r ' + refs, mkclasstype(`java.lang.Object' .class), st), validrefs(str, r ' + refs + r0 ', mkclasstype(`java.lang.Object' .class), st), is_valid_ref(str, r, st), validrefs(str, (r ' + refs) .last ' + r0 ', st[(r ' + refs) .last -- _type] .type, st) ⊦ r = r0, r = jvmref, step∃(str, (r ' + refs) .last, r0, st)
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ (r ' + refs) .butlast + (r ' + refs) .last ' + refs0 = r ' + refs + refs0], [CSIMPSEQ : ⊦ r ' ≠ []], [CSIMPSEQ : ⊦ ¬ refs + refs0 ≠ [] ↔ refs = [] ∧ refs0 = []], [CSIMPSEQ : ⊦ (r ' + refs) .first = r], [CSIMPSEQ : ⊦ (refs + refs0) + refs1 = refs + refs0 + refs1])]]