| ⊦ r = r0, is_obj(r, class, st -- r0) ↔ is_obj(r, class, 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(class)) ∈ st -- r0 ∧ goodfieldsandtypes(r, instfields(class), st -- r0) ↔ is_obj(r, class, st)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st -- r0, class, r)]]