| ⊦ m < # x → (a ∈ x[m, b] ↔ a = b ∨ a ∈ x -1l x[m]) |
∀ m, a, b. m < # x0 → (a ∈ x0[m, b] ↔ a = b ∨ a ∈ x0 -1l x0[m]) ⊦ m < #(a0 + x0) → (a ∈ (a0 + x0)[m, b] ↔ a = b ∨ a ∈ (a0 + x0) -1l (a0 + x0)[m])
Used simplifier rules: del1-e: ⊦ [] -1l a = [];%put-in-02: ⊦ m < # x → a ∈ x[m, a];%list freely generated by [], +;;%in-empty: ⊦ ¬ a ∈ []; from specification list%size-01: ⊦ # [] = 0; from specification list-data%zero-01: ⊦ ¬ m < 0; from specification nat-basic1