| m0 < # x0, m ≤ # x0, ∀ m, n, a. m < # x0 ∧ n < # x0 → (a ∈ x0[m, x0[n]][n, x0[m]] ↔ a ∈ x0) ⊦ x0 = [], m = 0, a ∈ (a0 ' + x0)[m, x0[m0]][m0 + 1, x0[m - 1]] ↔ a = a0 ∨ a ∈ x0 |
m = m1 + 1, m0 < # x0, m ≤ # x0, ∀ m, n, a. m < # x0 ∧ n < # x0 → (a ∈ x0[m, x0[n]][n, x0[m]] ↔ a ∈ x0) ⊦ x0 = [], m = 0, a ∈ (a0 ' + x0)[m, x0[m0]][m0 + 1, x0[m1]] ↔ a = a0 ∨ a ∈ x0
Used simplifier rules: n ≠ 0 ⊦ m = n - 1 ↔ n = m + 1; (elim) Used terms: m, m2