| ∀ y. filter(rmdup(x0), y) = rmdup(filter(x0, y)) ⊦ a ∈ y, filter(rmdup(a ' + x0), y) = rmdup(filter(a ' + x0, y)) |
∀ y. filter(rmdup(x0), y) = rmdup(filter(x0, y)) ⊦ filter(rmdup(a ' + x0), y) = rmdup(filter(x0, y)), a ∈ y
Used simplifier rules: filt-n: ⊦ ¬ a ∈ y → filter(a ' + x, y) = filter(x, y);%a: ⊦ (x + y) + z = x + y + z; from specification list