| is_fskey(sk), is_fskey(sk) ⊦ (addarray(r, vals, j, st)[r -- sk, val][r -- i ']) = (addarray(r, vals, j, st)[r -- i ']) |
is_fskey(sk) ⊦ ((i ' = sk ⊃ val; addarray(r, vals, j, st)[r -- i '])) = (addarray(r, vals, j, st)[r -- i '])
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ r -- sk = r0 -- sk0 ↔ ¬ ¬ (r = r0 ∧ sk = sk0)], [CSIMPSEQ : ⊦ (st[rk0, val][rk]) = ((rk = rk0 ⊃ val; st[rk]))])]]