| ∀ char, char0, str, str0. char < char0 ∧ char0 ' + str < str1 ∧ (∀ str3, char, str0. str < str3 ∧ char ' + str0 < str ∧ (∀ str2, str3. str0 < str2 ∧ str2 < str3 → str0 < str3) → char ' + str0 < str3) ∧ (∀ str2, str3. str0 < str2 ∧ str2 < str3 → str0 < str3) → char ' + str0 < str1, char < char0, char0 ' + str < char1 + str1, ∀ str3, char, str0. str < str3 ∧ char ' + str0 < str ∧ (∀ str2, str3. str0 < str2 ∧ str2 < str3 → str0 < str3) → char ' + str0 < str3, ∀ str2, str3. str0 < str2 ∧ str2 < str3 → str0 < str3 ⊦ char ' + str0 < char1 + str1 |
char < char0, char0 ' + str < char1 ' + str1, ∀ char, char0, str, str0. char < char0 ∧ char0 ' + str < str1 ∧ (∀ str3, char, str0. str < str3 ∧ char ' + str0 < str ∧ (∀ str2, str3. str0 < str2 ∧ str2 < str3 → str0 < str3) → char ' + str0 < str3) ∧ (∀ str2, str3. str0 < str2 ∧ str2 < str3 → str0 < str3) → char ' + str0 < str1, ∀ str3, char, str0. str < str3 ∧ char ' + str0 < str ∧ (∀ str2, str3. str0 < str2 ∧ str2 < str3 → str0 < str3) → char ' + str0 < str3, ∀ str2, str3. str0 < str2 ∧ str2 < str3 → str0 < str3 ⊦ char < char1, char = char1 ∧ str0 < str1
Used simplifier rules: Less-rec: ⊦ char1 ' + str1 < char2 ' + str2 ↔ char1 < char2 ∨ char1 = char2 ∧ str1 < str2;%assoc: ⊦ (str1 + str2) + str3 = str1 + str2 + str3; from specification string-append%chartostring-01: ⊦ char + str = char ' + str; from specification string-append