function t = isletter(c)
%ISLETTER True for letters of the alphabet.
%	For a string S, ISLETTER(S) is 1 for letters of the alphabet
%	and 0 otherwise.

%	Copyright (c) 1984-93 by The MathWorks, Inc.

t = (('a' <= c) & (c <= 'z')) | (('A' <= c) & (c <= 'Z'));
