char= char< char<= char> char>= char/= char-equal

(char= character &rest characters) -- (char< character &rest characters) -- (char<= character &rest characters) -- (char> character &rest characters) -- (char>= character &rest characters) -- (char/= character &rest characters) -- (char-equal character &rest characters)

Compare characters by their code points and return t or nil. All are variadic: char= is true when every argument is the same character, char</char<= when the arguments are in strictly increasing / non-decreasing order, char>/char>= when they are in strictly decreasing / non-increasing order, char/= when ALL arguments are pairwise distinct, and char-equal is the case-insensitive char=.