| 58 = n0 + 28, 28 ≤ pos('Z', sortedchars), 29 ≤ pos('Z', sortedchars), 28 ≤ 29, 28 ≤ 58 ⊦ pos('Z', sortedchars) = 0, s→l(sortedchars)[29 + n0] = 'b' |
29 ≤ pos('Z', sortedchars), 28 ≤ pos('Z', sortedchars) ⊦ pos('Z', sortedchars) = 0, s→l(sortedchars)[59] = 'b'
Used simplifier rules: ⊦ m + n = n + m;% ⊦ (m + n0) + n1 = m + n0 + n1;%n0 < n ⊦ (* n) = m0 + (* n0) ↔ n - n0 = m0;