| disj(x, y0), ∀ x. disj(rev(x), y0) ↔ disj(x, y0) ⊦ a ∈ x, disj(rev(x), a ' + y0) |
Used simplifier rules: rev-in: ⊦ a ∈ rev(x) ↔ a ∈ x;%cons: ⊦ disj(x, y) → (disj(x, a ' + y) ↔ ¬ a ∈ x); from specification list-dup%a: ⊦ (x + y) + z = x + y + z; from specification list Used terms: x