| a0 ∈ x0, ∀ a. a ∈ rmdup(x0) ↔ a ∈ x0 ⊦ a ∈ rmdup(a0 ' + x0) ↔ a = a0 ∨ a ∈ x0 |
a0 ∈ x0, ∀ a. a ∈ rmdup(x0) ↔ a ∈ x0 ⊦ a ∈ rmdup(x0) ↔ a ∈ x0
Used simplifier rules: rmdup-y: ⊦ a ∈ x → rmdup(a ' + x) = rmdup(x);%a: ⊦ (x + y) + z = x + y + z; from specification list