char= char< char<=

(char= character &rest characters) -- (char< character &rest characters) -- (char<= character &rest characters)

Compare characters by their code points and return t or nil. All three are variadic and case-sensitive: char= is true when every argument is the same character, char< is true when the arguments are in strictly increasing code-point order, and char<= is true when they are in non-decreasing order.