| a0 ∈ a ' + y, ∀ a, y. x0 \ (a ' + y) = (x0 -l a) \ y ⊦ (a0 ' + x0) \ (a ' + y) = ((a0 ' + x0) -l a) \ y |
∀ a, y. x0 \ (a ' + y) = (x0 -l a) \ y, a0 = a ∨ a0 ∈ y ⊦ x0 \ (a ' + y) = ((a0 ' + x0) -l a) \ y
Used simplifier rules: diff-y: ⊦ a ∈ y → (a ' + x) \ y = x \ y;%in-rec: ⊦ a ∈ b ' + x ↔ ¬ ¬(a = b ∨ a ∈ x); from specification list%a: ⊦ (x + y) + z = x + y + z; from specification list