| is_fskey(sk), ∀ class, st, r, i, val. addclass(class, fis0, st[r -- i ', val]) = (addclass(class, fis0, st)[r -- i ', val]) ⊦ addclass(class, fis0, st[r -- i ', val]) = (addclass(class, fis0, st)[r -- i ', val]), sk .fs .class = class |
sk = fs ', is_fskey(sk), ∀ class, st, r, i, val. addclass(class, fis0, st[r -- i ', val]) = (addclass(class, fis0, st)[r -- i ', val]) ⊦ addclass(class, fis0, st[r -- i ', val]) = (addclass(class, fis0, st)[r -- i ', val]), fs .class = class
[[CONCRETESIMPRULES : ([CSIMPELIM : ⊦ is_fskey(sk) → (fs = sk .fs ↔ sk = fs ')])], [EXTRATERMS : (sk, fs)]]