| m0 < # x0, ∀ m, a. m < # x0 → (a ∈ x0[m, a] -1l a ↔ a ∈ x0) ∨ x0[m] = a ⊦ a ∈ (a0 ' + x0[m0, a]) -1l a ↔ a = a0 ∨ a ∈ x0, x0[m0] = a, x0 = [] |
m0 < # x0, ∀ m, a. m < # x0 → (a ∈ x0[m, a] -1l a ↔ a ∈ x0) ∨ x0[m] = a ⊦ a ∈ (a0 ' + x0[m0, a]) -1l a ↔ a = a0 ∨ a ∈ x0, x0[m0] = a, a = a0, x0 = []
Used simplifier rules: del1-y: ⊦ (a ' + x) -1l a = x;%put-in: ⊦ a ≠ x[m] ∧ m < # x → (a ∈ x[m, b] ↔ a = b ∨ a ∈ x);%put-in-02: ⊦ m < # x → a ∈ x[m, a];%a: ⊦ (x + y) + z = x + y + z; from specification list Used formulas: a = a0