| a0 = a, #oc(a0, y) < #oc(a0, a ') + #oc(a0, x), a ∈ y, ∀ a0. #oc(a0, x) ≤ #oc(a0, y -1l a) ⊦ |
a ∈ y, #oc(a, y) ≤ #oc(a, x), ∀ a0. #oc(a0, x) ≤ #oc(a0, y -1l a) ⊦
Used simplifier rules: one: ⊦ #oc(a, a ') = 1;% ⊦ m < n ↔ ¬ n ≤ m; (ss)%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ m < n + 1 ↔ ¬ n < m; (s)