| validrefval(str, val, ty, st), st ⊆ st0 ⊦ validrefval(str, val, ty, st0) |
⊦ validrefval(str, val, ty, st) ↔ is_referencevalue(val) ∧ validref(str, val .refval, ty, st)
validrefval(str, val, ty, st), st ⊆ st0 ⊦ is_referencevalue(val) ∧ validref(str, val .refval, ty, st0)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st0, ty, val, str)]]