| # x + # y0 = # y0 - 1, a ∈ y0, ∀ x, a. # x + # y0 = #(y0 -1l a) → x = [] ∧ ¬ a ∈ y0 ⊦ a = a0 |
Used simplifier rules: ⊦ m = m + n ↔ n = 0; (s)% ⊦ m + 1 ≠ 0; (s)%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic%c: ⊦ m + n = n + m; from specification nat-basic% ⊦ # x = 0 ↔ x = []; (s)% ⊦ # [] = 0; (s)% ⊦ n + 0 = n; (s)% ⊦ ¬ a ∈ []; (s)%n ≠ 0 ⊦ m = n - 1 ↔ n = m + 1; (elim) Used terms: # y0, m