issep : string -> bool

SYNOPSIS
Tests if a one-character string is a separator.

DESCRIPTION
The call issep s tests whether the first character of string s (normally it is the only character) is one of the separators `,' or `;'.

FAILURE CONDITIONS
Fails if the string is empty.

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