| x ⊑ x0, ordered≤(x0) ⊦ ordered≤(x) |
∀ x0. x1 ⊑ x0 ∧ ordered≤(x0) → ordered≤(x1), a + x1 ⊑ x0, ordered≤(x0) ⊦ ordered≤(a + x1)
Used simplifier rules: le-e: ⊦ ordered≤([]);%list freely generated by [], +;;%prefix-nil: ⊦ [] ⊑ x; from specification list-last