| ∀ a, y. x0 ⊆m a ' + y ↔ #oc(a, x0) ≤ #oc(a, y) + 1 ∧ x0 -1l a ⊆m y ⊦ (a0 = a ∨ a0 ∈ y) ∧ x0 ⊆m (a ' + y) -1l a0 ↔ #oc(a, a0 ') + #oc(a, x0) ≤ #oc(a, y) + 1 ∧ (a0 ' + x0) -1l a ⊆m y |
∀ a, y. x0 ⊆m a ' + y ↔ #oc(a, x0) ≤ #oc(a, y) + 1 ∧ x0 -1l a ⊆m y ⊦ a = a0, (a0 = a ∨ a0 ∈ y) ∧ x0 ⊆m (a ' + y) -1l a0 ↔ #oc(a, a0 ') + #oc(a, x0) ≤ #oc(a, y) + 1 ∧ (a0 ' + x0) -1l a ⊆m y
Used simplifier rules: one: ⊦ #oc(a, a ') = 1;%oc: ⊦ x ⊆m y → ¬ #oc(a, y) < #oc(a, x);%del1-y: ⊦ (a ' + x) -1l a = x; from specification list-del%a: ⊦ (x + y) + z = x + y + z; from specification list%lep-02: ⊦ m + n ≤ m + n0 ↔ n ≤ n0; from specification nat%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic2%c: ⊦ m + n = n + m; from specification nat-basic2%lels-01: ⊦ ¬ m ≤ n ↔ n < m; from specification nat Used formulas: a = a0