| ordered<(a ' + x), b < a, b ∈ x ⊦ |
∀ a, b. ¬(ordered<(a ' + x0) ∧ b < a ∧ b ∈ x0), ordered<(a ' + (a0 + x0)), b < a, b ∈ a0 + x0 ⊦
Used simplifier rules: ls-o: ⊦ ordered<(a ');%list freely generated by [], +;;%app: ⊦ x + [] = x; from specification list%a: ⊦ (x + y) + z = x + y + z; from specification list%in-empty: ⊦ ¬ a ∈ []; from specification list