- LetterQ[string] by default gives False if string contains any space or punctuation characters.
- LetterQ handles both ordinary and special characters.
- LetterQ treats as letters all special characters explicitly listed as letters in the table in "Named Characters".
- In general, LetterQ treats as letters all characters that appear as ordinary text in any language.
- LetterQ treats as letters such special characters as , , , and .
- LetterQ does not treat as letters (\[EmptySet]), (\[HBar]), (\[Angstrom]), or (\[Sum]).
Introduced in 1991
(2.0)| Updated in 1996