| validrefs(str, r ' + acc, ty, st), validrefs(str, acc .last ' + refs1, ty0, st), is_valid_ref(str, r, st), st[r -- _type] .type ≤ ty, ∀ str0, ty1, st0, refs, ty2. validrefs(str0, acc, ty1, st0) ∧ validrefs(str0, acc .last ' + refs, ty2, st0) → validrefs(str0, acc + refs, ty1, st0) ⊦ acc = [], r = jvmref, validrefs(str, (r ' + acc) + refs1, ty, st) |
⊦ 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, r, st) ∧ st[r -- _type] .type ≤ ty), validrefs(str, r ' + acc, ty, st), validrefs(str, acc .last ' + refs1, ty0, st), is_valid_ref(str, r, st), st[r -- _type] .type ≤ ty, ∀ str0, ty1, st0, refs, ty2. validrefs(str0, acc, ty1, st0) ∧ validrefs(str0, acc .last ' + refs, ty2, st0) → validrefs(str0, acc + refs, ty1, st0) ⊦ acc = [], r = jvmref, validrefs(str, (r ' + acc) + refs1, ty, st)
is_obj(str, r, st) ∧ st[r -- _type] .type ≤ ty, acc = [] ∨ (∃ fs. fs ' ∈ instfields(st[r -- _type] .type .class) ∧ is_referencevalue(st[r -- fs ']) ∧ acc .first = st[r -- fs '] .refval ∧ validrefs(str, acc, fs .type, st)), validrefs(str, acc .last ' + refs1, ty0, st), is_valid_ref(str, r, st), st[r -- _type] .type ≤ ty, ∀ str0, ty1, st0, refs, ty2. validrefs(str0, acc, ty1, st0) ∧ validrefs(str0, acc .last ' + refs, ty2, st0) → validrefs(str0, acc + refs, ty1, st0) ⊦ acc = [], r = jvmref, validrefs(str, (r ' + acc) + refs1, ty, st)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st, ty, acc, r, str)]]