m < #(a0 + x0), ∀ m, a, n. m < # x0 → x0[m, a][n] = x0[n] ∨ m = n ⊦ (a0 + x0)[m, a][n] = (a0 + x0)[n], m = n
Used simplifier rules: list freely generated by [], +;;% ⊦ # [] = 0; (s)% ⊦ ¬ n < 0; (s)