| m ≤ # x ⊦ ⌜x⌝ + σ to m = ⌜x to m⌝ |
m ≤ #(a + x0), ∀ m, σ. m ≤ # x0 → ⌜x0⌝ + σ to m = ⌜x0 to m⌝ ⊦ ⌜a + x0⌝ + σ to m = ⌜a + x0 to m⌝
Used simplifier rules: empty: ⊦ ⌜[]⌝ = [];%empty-append: ⊦ [] + σ = σ;%append-assoc: ⊦ (σ + σ1) + σ2 = σ + σ1 + σ2;%to-zero: ⊦ σ to 0 = [];%to-zero-l: ⊦ x to 0 = [];%list freely generated by [], +;;% ⊦ # [] = 0; (s)% ⊦ m ≤ 0 ↔ m = 0; (s)