| n < (# ar + # ar0) + # ar1, n < #(ar + ar0) + # ar1, # ar + # ar0 ≤ n, #(ar + ar0) ≤ n ⊦ # ar1 = 0, ar1[n - #(ar + ar0)] = (ar + ar0 + ar1)[n] |
⊦ #(ar0 + ar1) = # ar0 + # ar1
n < (# ar + # ar0) + # ar1, # ar + # ar0 ≤ n ⊦ # ar1 = 0, ar1[n - # ar + # ar0] = (ar + ar0 + ar1)[n]
Used simplifier rules: append-len: ⊦ #(ar0 + ar1) = # ar0 + # ar1;%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic