| st[r -- _type] .type ≤ ty ⊦ r = jvmref, validref(str, r, ty, st0 ∪ st), junkref(str, r, st) |
⊦ validref(str, r, ty, st) ↔ r = jvmref ∨ st[r -- _type] .type ≤ ty ∧ ¬ junkref(str, r, st)
st[r -- _type] .type ≤ ty ⊦ r = jvmref, r = jvmref ∨ (st0 ∪ st)[r -- _type] .type ≤ ty ∧ ¬ junkref(str, r, st0 ∪ st), junkref(str, r, st)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st0 ∪ st, ty, r, str)]]