| validref(str, r, ty, st), ¬ is_valid_ref(str, r, st) ∨ ¬ st[r -- _type] .type ≤ ty ⊦ r = jvmref |
⊦ validref(str, r, ty, st) ↔ r = jvmref ∨ st[r -- _type] .type ≤ ty ∧ ¬ junkref(str, r, st)
⊦ ¬ is_valid_ref(str, r, st) ∧ r ≠ jvmref → junkref(str, r, st)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st, ty, r, str)]]