| rev(x) + y = a ' + y0, rev(x) = a0 + y1, a ∈ x ∨ a ∈ y ⊦ rev(x) = [], x = [], y0 = y1 + y |
rev(x) + y = a ' + y0, rev(x) = a0 ' + y1, a0 ∈ x, a ∈ x ∨ a ∈ y ⊦ x = [], y0 = y1 + y
Used simplifier rules: rev-empty: ⊦ rev(x) = [] ↔ x = [];%rev-in: ⊦ a ∈ rev(x) ↔ a ∈ x;%a: ⊦ (x + y) + z = x + y + z; from specification list%in-14: ⊦ a ' + x = y → a ∈ y; (forward) from specification list% ⊦ a + x = a ' + x; (s)