| ∀ a, b. (x0 -l a) -l b = (x0 -l b) -l a ⊦ b = a0, a = a0, (a0 ' + (x0 -l a)) -l b = ((a0 ' + x0) -l b) -l a |
∀ a, b. (x0 -l a) -l b = (x0 -l b) -l a ⊦ b = a0, a = a0, (x0 -l a) -l b = (x0 -l b) -l a
Used simplifier rules: del-n: ⊦ a ≠ b → (b ' + x) -l a = b ' + (x -l a);%app-08: ⊦ a ' + x = a ' + y ↔ x = y; from specification list%a: ⊦ (x + y) + z = x + y + z; from specification list