| ∀ a. a ∈ x ↔ a ∈ y ⊦ dups(x), dups(y), ∀ a. #oc(a, y) ≤ #oc(a, x) |
#oc(a, y) = 1, #oc(a, x) = 0, ∀ a. a ∈ x ↔ a ∈ y ⊦ dups(y), dups(x)
Used simplifier rules: oc-dups: ⊦ n < #oc(a, x) ∧ ¬ dups(x) → #oc(a, x) = 1;% ⊦ 0 < n ↔ n ≠ 0; (s)%lf-02: ⊦ m < n ∧ m = n0 → n0 < n; (forward) from specification nat-basic% ⊦ m < 1 ↔ m = 0; (s)%lf-01: ⊦ m < n ∧ n = n0 → m < n0; (forward) from specification nat-basic% ⊦ m < n → n ≠ 0; (s)%f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic% ⊦ m ≤ n ↔ ¬ n < m; (ss)