isalpha : string -> bool

SYNOPSIS
Tests if a one-character string is alphabetic.

DESCRIPTION
The call isalpha s tests whether the first character of string s (normally it is the only character) is alphabetic, i.e. an uppercase or lowercase letter, an underscore or a prime character.

FAILURE CONDITIONS
Fails if the string is empty.

SEE ALSO
isalnum, isbra, isnum, issep, isspace, issymb.