| ¬ b ≠ a0, ∀ a, b. #oc(a, x0 -l b) = #oc(a, x0) ∨ a = b ⊦ a = a0, a = b, #oc(a, (a0 ' + x0) -l b) = #oc(a, x0) |
∀ a, b. #oc(a, x0 -l b) = #oc(a, x0) ∨ a = b ⊦ a = a0, #oc(a, x0 -l a0) = #oc(a, x0)
Used simplifier rules: a: ⊦ (x + y) + z = x + y + z; from specification list%del-y: ⊦ (a ' + x) -l a = x -l a; from specification list-del