| ∀ a. a ∈ ins≤(a, x0) ⊦ a ∈ ins≤(a, a0 ' + x0) |
a0 < a, ∀ a. a ∈ ins≤(a, x0) ⊦ a ∈ ins≤(a, a0 ' + x0)
Used simplifier rules: ins-y: ⊦ ¬ b < a → ins≤(a, b ' + x) = a + b + x;%c: ⊦ a + x = a ' + x; from specification list%a: ⊦ (x + y) + z = x + y + z; from specification list%in-06: ⊦ ¬ a ∈ b ' + x ↔ a ≠ b ∧ ¬ a ∈ x; from specification list Used formulas: a0 < a