| char < char2, pos(char2, sortedchars) < pos(char3, sortedchars) ⊦ char < char3 |
⊦ char1 < char2 ↔ pos(char1, sortedchars) < pos(char2, sortedchars)
pos(char2, sortedchars) < pos(char3, sortedchars), pos(char, sortedchars) < pos(char2, sortedchars) ⊦ char < char3
Used terms: char2, char