| st -- r ⊆ st -- (r -- sk) → # (st -- r) ≤ # (st -- (r -- sk)), r -- sk ∈ st, # st ≤ # (st -- r), r ∈ st ⊦ |
r -- sk ∈ st, # st ≤ # (st -- r), r ∈ st, st -- r ⊆ st -- (r -- sk) → # (st -- r) ≤ # st - 1 ⊦
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ n -1 = n - 1], [CSIMPSEQ : ⊦ rk ∈ st → # (st -- rk) = (# st) -1])]]