| a0 < a, ∀ a. ins≤(a, x0) -1l a = x0 ⊦ a0 ' + (ins≤(a, x0) -1l a) = a0 ' + x0, a = a0 |
a0 < a, ∀ a. ins≤(a, x0) -1l a = x0 ⊦ ins≤(a, x0) -1l a = x0, a = a0
Used simplifier rules: a: ⊦ (x + y) + z = x + y + z; from specification list% ⊦ x + y = x + z ↔ y = z; (s)