| is_obj(str, r0, st), validrefs(str, r0 ' + acc, ty, st), st ⊆ st0, st[r0 -- _type] .type ≤ ty, ∀ str0, ty0, st1, st2. validrefs(str0, acc, ty0, st1) ∧ st1 ⊆ st2 ∧ ¬ junkref(str0, acc .first, st1) ∧ acc ≠ [] → validrefs(str0, acc, ty0, st2) ⊦ r0 = jvmref, junkref(str, r0, st), validrefs(str, r0 ' + acc, ty, st0) |
⊦ is_obj(str, r, st) ∧ st[r -- _type] .type ≤ ty → ( validrefs(str, r ' + refs, ty, st) ↔ refs = [] ∨ (∃ fs. fs ' ∈ instfields(st[r -- _type] .type .class) ∧ is_referencevalue(st[r -- fs ']) ∧ refs .first = st[r -- fs '] .refval ∧ validrefs(str, refs, fs .type, st)))
is_obj(str, r0, st) ∧ st[r0 -- _type] .type ≤ ty, is_obj(str, r0, st), acc = [] ∨ (∃ fs. fs ' ∈ instfields(st[r0 -- _type] .type .class) ∧ is_referencevalue(st[r0 -- fs ']) ∧ acc .first = st[r0 -- fs '] .refval ∧ validrefs(str, acc, fs .type, st)), st ⊆ st0, st[r0 -- _type] .type ≤ ty, ∀ str0, ty0, st1, st2. validrefs(str0, acc, ty0, st1) ∧ st1 ⊆ st2 ∧ ¬ junkref(str0, acc .first, st1) ∧ acc ≠ [] → validrefs(str0, acc, ty0, st2) ⊦ r0 = jvmref, junkref(str, r0, st), validrefs(str, r0 ' + acc, ty, st0)
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ (refs + refs0) + refs1 = refs + refs0 + refs1])], [EXTRATERMS : (st, ty, acc, r0, str)]]