| below(ns, n) = ∅ ⊦ below(ns -- m, n) = ∅ |
Used simplifier rules: below-rem-notin: n ≤ m ⊦ below(ns -- m, n) = below(ns, n);%below-rem-in: n > m ⊦ below(ns -- m, n) = below(ns, n) -- m;% ⊦ ∅ -- n = ∅; (s)%size-zero: ⊦ # ns ≠ 0 → ns ≠ ∅; (forward) from specification set-basic[nat-set]% ⊦ m < n ↔ ¬ n ≤ m; (ss)% ⊦ m > n ↔ n < m; (s)%size-zero-01: ⊦ ns ≠ ∅ → # ns ≠ 0; (forward) from specification set-basic[nat-set]