| ⊦ r ≠ r0 → (is_valid_ref(str, r, addobj(r0, class, fis, st)) ↔ is_valid_ref(str, r, st)) |
⊦ is_valid_ref(str, r, st) ↔ ¬ ¬ (is_valid_ref(r, st) ∧ (is_obj(str, r, st) ∨ is_array(str, r, st)))
⊦ r ≠ r0 → (is_valid_ref(r, addobj(r0, class, fis, st)) ↔ is_valid_ref(r, st))
⊦ is_obj(str, r, st) ↔ class+∃(str, st[r -- _type] .type .class) ∧ ¬ is_abstract(st[r -- _type] .type .class) ∧ is_obj(r, st)
⊦ r ≠ r0 → (addobj(r, class1, fis, st)[r0 -- sk]) = st[r0 -- sk]
⊦ r ≠ r0 → (is_obj(r, addobj(r0, class, fis, st)) ↔ is_obj(r, st))
⊦ is_valid_ref(str, r, st) ↔ is_obj(str, r, st) ∨ is_array(str, r, st)
⊦ r = r0, is_valid_ref(r, st) ∧ ( class+∃(str, st[r -- _type] .type .class) ∧ ¬ is_abstract(st[r -- _type] .type .class) ∧ is_obj(r, st) ∨ is_array(str, r, addobj(r0, class, fis, st))) ↔ is_obj(str, r, st) ∨ is_array(str, r, st)
[[CONCRETESIMPRULES : ()]]