| pos(b, a0 ' + x0) = pos(a, x0) + 1, a ∈ x0, ∀ b, a. pos(b, x0) = pos(a, x0) ∧ a ∈ x0 → a = b ⊦ a = b, a = a0 |
⊦ a ≠ b → pos(a, b ' + x) = pos(a, x) + 1
b ≠ a0, pos(b, x0) + 1 = pos(a, x0) + 1, a ∈ x0, ∀ b, a. pos(b, x0) = pos(a, x0) ∧ a ∈ x0 → a = b ⊦ a = b, a = a0
Used simplifier rules: pos-y: ⊦ pos(a, a ' + x) = 0;%a: ⊦ (x + y) + z = x + y + z; from specification list%z-01: ⊦ m + n = 0 ↔ m = 0 ∧ n = 0; from specification nat-basic2%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic2%c: ⊦ m + n = n + m; from specification nat-basic2 Used terms: x0, a0, b