| ⊦ r = r0, is_obj(r, class0, addobj(r0, class, fis, st)) ↔ is_obj(r, class0, st) |
⊦ is_obj(r, class, st) ↔ r ≠ jvmref ∧ (r -- _type) × typeval(mkclasstype(class)) ∈ st ∧ goodfieldsandtypes(r, instfields(class), st)
⊦ r = r0, r ≠ jvmref ∧ (r -- _type) × typeval(mkclasstype(class0)) ∈ addobj(r0, class, fis, st) ∧ goodfieldsandtypes(r, instfields(class0), addobj(r0, class, fis, st)) ↔ is_obj(r, class0, st)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (addobj(r0, class, fis, st), class0, r)]]