| m < 8, ∀ m1, char. m1 < (m + 1) + 1 → true → ¬ char ∈ '0' + '1' + '2' + '3' + '4' + '5' + '6' + '7' + ('8' + '9') → ¬ char ∈ s→l(n→s(m1)) ⊦ m = 0, ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '1', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '2', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '3', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '4', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '5', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '6', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '7', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '8', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '9', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m - 1] = '0' |
m = m0 + 1, m < 8, ∀ m1, char. m1 < (m + 1) + 1 → true → ¬ char ∈ '0' + '1' + '2' + '3' + '4' + '5' + '6' + '7' + ('8' + '9') → ¬ char ∈ s→l(n→s(m1)) ⊦ m = 0, ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '1', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '2', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '3', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '4', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '5', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '6', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '7', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '8', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '9', ('3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ')[m0] = '0'
Used simplifier rules: n ≠ 0 ⊦ m = n - 1 ↔ n = m + 1; (elim) Used terms: m, m0