| ¬ char ∈ '0' + '1' + '2' + '3' + '4' + '5' + '6' + '7' + ('8' + '9') → ¬ char ∈ s→l(n→s(m / 10)), 10 ≤ m, ∀ m1, char. m1 < m → true → ¬ char ∈ '0' + '1' + '2' + '3' + '4' + '5' + '6' + '7' + ('8' + '9') → ¬ char ∈ s→l(n→s(m1)) ⊦ char = '0', char = '9', char = '8', char = '7', char = '6', char = '5', char = '4', char = '3', char = '2', char = '1', m = 0, ¬ char ∈ s→l(n→s(m / 10)) ∧ ¬ char ∈ s→l(n→s(m % 10)) |
10 ≤ m, char ∈ s→l(n→s(m % 10)), ∀ m1, char. m1 < m → true → ¬ char ∈ '0' + '1' + '2' + '3' + '4' + '5' + '6' + '7' + ('8' + '9') → ¬ char ∈ s→l(n→s(m1)) ⊦ char = '0', char = '9', char = '8', char = '7', char = '6', char = '5', char = '4', char = '3', char = '2', char = '1', m = 0, char ∈ s→l(n→s(m / 10))
Used simplifier rules: ⊦ (chars + chars0) + chars1 = chars + chars0 + chars1;% ⊦ char ∈ char0 ' ↔ char = char0;% ⊦ char ≠ char0 → (char ∈ char0 ' + chars ↔ char ∈ chars);% ⊦ char + chars = char ' + chars;% ⊦ char + char0 = char ' + char0 ';