| is_fskey(fv .1), ∀ str, r, ty, class, st. validref(str, r, ty, addclass(class, fis0, st)) ↔ validref(str, r, ty, st) ⊦ fv .1 .fs .class = class, validref(str, r, ty, addclass(class, fis0, st)) ↔ validref(str, r, ty, st) |
fv = sk × val, is_fskey(sk), ∀ str, r, ty, class, st. validref(str, r, ty, addclass(class, fis0, st)) ↔ validref(str, r, ty, st) ⊦ sk .fs .class = class, validref(str, r, ty, addclass(class, fis0, st)) ↔ validref(str, r, ty, st)
[[CONCRETESIMPRULES : ([CSIMPELIM : ⊦ sk = fv .1 ∧ val = fv .2 ↔ fv = sk × val])], [EXTRATERMS : (fv, sk, val)]]