| ∀ y, a. (x0 + y) -l a = (x0 -l a) + (y -l a) ⊦ a = a0, ((a0 ' + x0) + y) -l a = ((a0 ' + x0) -l a) + (y -l a) |
∀ y, a. (x0 + y) -l a = (x0 -l a) + (y -l a) ⊦ a = a0, (x0 + y) -l a = (x0 -l a) + (y -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