% This macro source file is from the four volume series
% "TeX in Practice" by Stephan von Bechtolsheim, published
% 1993 by Springer-Verlag, New York.
% Copyright 1993 Stephan von Bechtolsheim.
% No warranty or liability is assumed.
% This macro may be copied freely if no fees other than
% media cost or shipping charges are charged and as long
% as this copyright and the following source code itself
% is not changed. Please see the series for further information.
%
% Version: 1.0
% Date: May 1, 1993
%
%
% This source code is documented in 21.5.6, p. III-173.
% Original source in file "macros1.TEX", starting line 1179.
\wlog{L: "testdef.tip" ["macros1.TEX," l. 1179, p. III-173]}%
% This file DOES belong to format "texip."
\catcode`\@ = 11
\newif\if@Defined
\def\DefinedConditional #1{%
    TT\fi
    \ifx\@UndefinedToken #1% 
        \@Definedfalse
    \else
        \@Definedtrue
    \fi
    \if@Defined
}
\catcode`\@ = 12