| is_fskey(sk) ⊦ sk .fs .class = class, addclass(class, (sk × val) ' + fis, st) = addclass(class, fis, st) |
sk = fs ', is_fskey(sk) ⊦ fs .class = class, addclass(class, (sk × val) ' + fis, st) = addclass(class, fis, st)
[[CONCRETESIMPRULES : ([CSIMPELIM : ⊦ is_fskey(sk) → (fs = sk .fs ↔ sk = fs ')])], [EXTRATERMS : (sk, fs)]]