| ¬ ¬ a ∈ z, ∀ z. rmdup(y0) \ z = rmdup(y0 \ z) ⊦ (a ' + rmdup(y0)) \ z = rmdup((a ' + y0) \ z), a ∈ y0 |
a ∈ z, ∀ z. rmdup(y0) \ z = rmdup(y0 \ z) ⊦ rmdup(y0) \ z = rmdup(y0 \ z), a ∈ y0
Used simplifier rules: diff-y: ⊦ a ∈ y → (a ' + x) \ y = x \ y;%a: ⊦ (x + y) + z = x + y + z; from specification list