% 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 24.1.15.1, p. III-293.
% Original source in file "macros4.TEX", starting line 661.
\wlog{L: "testsubs.tip" ["macros4.TEX," l. 661, p. III-293]}%
% This file DOES belong to format "texip."
\InputD{showx.tip}
\catcode`\@ = 11
\newif\if@TestSubString
\def\SubStringConditional #1#2{%
    TT\fi
    \edef\@MainString{#1}%
    \edef\@SubStringConditionalTemp{{#1}{#2}}%
    \expandafter\@SubStringConditional\@SubStringConditionalTemp
}
\def\@SubStringConditional #1#2{% 
    \def\@TestSubS ##1#2##2\@Del{% 
        \def\@TestTemp{##1}% 
    }% 
    \ShowX{\@TestSubS}%
    \@TestSubS #1#2\@Del
    \ShowX{\@TestTemp}%
    \ifx\@MainString\@TestTemp
        \@TestSubStringfalse
    \else
        \@TestSubStringtrue
    \fi
    \if@TestSubString
}
\catcode`\@ = 12