| ¬ ¬ a ∈ (x0 \ z) + (y \ z), a ∈ x0 ∨ a ∈ y, ∀ y0, z0. rmdup(x0 + y0) \ z0 = rmdup((x0 \ z0) + (y0 \ z0)) ⊦ rmdup(x0 + y) \ z = rmdup((a ' + (x0 \ z)) + (y \ z)), a ∈ z |
a ∈ x0 ∨ a ∈ y, ∀ y0, z0. rmdup(x0 + y0) \ z0 = rmdup((x0 \ z0) + (y0 \ z0)), a ∈ x0 \ z ∨ a ∈ y \ z ⊦ rmdup(x0 + y) \ z = rmdup((x0 \ z) + (y \ z)), a ∈ z
Used simplifier rules: in-append: ⊦ a ∈ x + y ↔ ¬ ¬(a ∈ x ∨ a ∈ y); from specification list%a: ⊦ (x + y) + z = x + y + z; from specification list%rmdup-y: ⊦ a ∈ x → rmdup(a ' + x) = rmdup(x); from specification list-dup