| is_reftype(ty1), ty ≤ ty1, validref(str, r1, ty, st), validref(str, r, ty0, st) ⊦ validref(str, r, ty0, st[r0 -- mkfs(class, ty1, fieldvar) ', refval(r1)]) |
⊦ validref(str, r, ty, st) ↔ r = jvmref ∨ st[r -- _type] .type ≤ ty ∧ ¬ junkref(str, r, st)
is_reftype(ty1), ty ≤ ty1, validref(str, r1, ty, st), r = jvmref ∨ st[r -- _type] .type ≤ ty0 ∧ ¬ junkref(str, r, st) ⊦ validref(str, r, ty0, st[r0 -- mkfs(class, ty1, fieldvar) ', refval(r1)])
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st, ty0, r, str)]]