%% S. Lurp --- STRETCHY docs --- MIT License
Stretchy provides the stretchy symbols listed below.

\subsection{Repeated symbols}

Stretchy provides methods of repeating symbols, while also adding stretched material to it.
These symbols are:

\macroexp{\strtyint {<N>}{<sup>}{<sub>}/crcr
\strtyintlimits {<N>}{<sup>}{<sub>}}
This prints {\it N} integral signs, with {\it sup} and {\it sub} as superscript and subscript material,
respectively.
\macro\strtyint{} differs from \macro\strtyintlimits{} regarding where the limits are placed.
The former places them next to the symbols, the latter above and below.

For example, \inlinecode|\strtyint{5}{}{{\bb R}^5}| and \inlinecode|\strtyintlimits{5}{}{{\bb R}^5}| prints
$$ \strtyint{5}{}{{\bb R}^5} \quad \strtyintlimits{5}{}{{\bb R}^5} $$
\emacroexp

\macroexp{\strtyoint {<N>}{<sup>}{<sub>}/crcr
\strtyointlimits {<N>}{<sup>}{<sub>}}
This prints {\it N} integral signs with a circle stretched out painted on them.
{\it sup} and {\it sub} are the superscript and subscript material respectively.
\macro\strtyoint{} differs from \macro\strtyointlimits{} regarding where the limits are placed.
The former places them next to the symbols, the latter above and below.

For example, \inlinecode|\strtyoint{5}{}{\partial S}| and \inlinecode|\stryointlimits{5}{}{\partial S}| prints
$$ \strtyoint{5}{}{\partial S} \quad \strtyointlimits{5}{}{{\bb R}^5} $$
\emacroexp

\macroexp{\strtysqint {<N>}{<sup>}{<sub>}/crcr
\strtysqintlimits {<N>}{<sup>}{<sub>}}
This prints {\it N} integral signs with a square stretched out painted on them.
{\it sup} and {\it sub} are the superscript and subscript material respectively.
\macro\strtysqint{} differs from \macro\strtysqintlimits{} regarding where the limits are placed.
The former places them next to the symbols, the latter above and below.

For example, \inlinecode|\strtysqint{5}{}{\partial S}| and \inlinecode|\strysqintlimits{5}{}{\partial S}| prints
$$ \strtysqint{5}{}{\partial S} \quad \strtysqintlimits{5}{}{{\bb R}^5} $$
\emacroexp

\macroexp{\strtyrsqint {<N>}{<sup>}{<sub>}/crcr
\strtyrsqintlimits {<N>}{<sup>}{<sub>}}
This prints {\it N} integral signs with a rounded square stretched out painted on them.
{\it sup} and {\it sub} are the superscript and subscript material respectively.
\macro\strtyrsqint{} differs from \macro\strtyrsqintlimits{} regarding where the limits are placed.
The former places them next to the symbols, the latter above and below.

For example, \inlinecode|\strtyrsqint{5}{}{\partial S}| and \inlinecode|\stryrsqintlimits{5}{}{\partial S}| prints
$$ \strtyrsqint{5}{}{\partial S} \quad \strtyrsqintlimits{5}{}{{\bb R}^5} $$
\emacroexp

\macroexp{\strtytriint {<N>}{<sup>}{<sub>}/crcr
\strtytriintlimits {<N>}{<sup>}{<sub>}}
This prints {\it N} integral signs with a triangle stretched out painted on them.
{\it sup} and {\it sub} are the superscript and subscript material respectively.
\macro\strtytriint{} differs from \macro\strtytriintlimits{} regarding where the limits are placed.
The former places them next to the symbols, the latter above and below.

For example, \inlinecode|\strtytriint{5}{}{\partial S}| and \inlinecode|\strytriintlimits{5}{}{\partial S}| prints
$$ \strtytriint{5}{}{\partial S} \quad \strtytriintlimits{5}{}{{\bb R}^5} $$
\emacroexp

\macroexp{\pii {<N>}}
Prints $\pi$ with {\it N} legs.
This can be used for fractions of $\pi$.
That is, \inlinecode|\pii{N}| corresponds to the value $2\pi/N$.
For example, \inlinecode|\pii{5}| gives $\pii{5}$
\emacroexp

\subsection{Stretched symbols}

Stretchy provides methods of stretching symbols, allowing them to grow arbitrarily large.
These symbols are:

\macroexp{\xint {<sup>}{<sub>}{<material>}}
This draws an integral sign stretched to match the height and depth of {\it material} with superscript and
subscript material corresponding to {\it sup} and {\it sub} respectively.

For example \inlinecode|\xint {-3}{-2}{\sum_{n=1}^\infty n^x\,dx}| produces
$$ \xint {-3}{-2}{\sum_{n=1}^\infty n^x\,dx} $$
\emacroexp

\macroexp{\xhsum {<sup>}{<sub>}/crcr
\xvsum {<sup>}{<sub>}{<material>}/crcr
\xhvsum {<sup>}{<sub>}{<material>}}
\blist
    \item \macro\xhsum{} paints a summation symbol stretched horizontally to match the width of its limits;
    \item \macro\xvsum{} paints a summation symbol stretched vertically to match the height and depth of
        {\it material} with the specified limits;
    \item \macro\xhvsum{} paints a summation symbol stretched both horizontally (to match the width of its
        limits) and vertically (to match the height and depth of {\it material}).
\elist
For example,
\begincode
\xhsum {}{n\in\{2a+3b\;\mid\;a,b\in{\bb Z}\}}{1\over n}
\xvsum {}{n\in\{2a+3b\;\mid\;a,b\in{\bb Z}\}}{{1\over n}}
\xhvsum {}{n\in\{2a+3b\;\mid\;a,b\in{\bb Z}\}}{{1\over n}}
/endcode
$$
\xhsum {}{n\in\{2a+3b\;\mid\;a,b\in{\bb Z}\}}{1\over n};\qquad
\xvsum {}{n\in\{2a+3b\;\mid\;a,b\in{\bb Z}\}}{{1\over n}};\qquad
\xhvsum {}{n\in\{2a+3b\;\mid\;a,b\in{\bb Z}\}}{{1\over n}}
$$
\emacroexp

\macroexp{\xhbigcup {<sup>}{<sub>}/crcr
\xvbigcup {<sup>}{<sub>}{<material>}/crcr
\xhvbigcup {<sup>}{<sub>}{<material>}}
\blist
    \item \macro\xhbigcup{} paints a big-cup symbol stretched horizontally to match the width of its limits;
    \item \macro\xvbigcup{} paints a big-cup symbol stretched vertically to match the height and depth of
        {\it material} with the specified limits;
    \item \macro\xhvbigcup{} paints a big-cup symbol stretched both horizontally (to match the width of its
        limits) and vertically (to match the height and depth of {\it material}).
\elist
For example,
\begincode
\xhbigcup{}{f\in L^2(\mu),\int f>0}\left\{{1\over f},f\right\};\qquad
\xvbigcup{}{f\in L^2(\mu),\int f>0}{\left\{{1\over f},f\right\}};\qquad
\xhvbigcup{}{f\in L^2(\mu),\int f>0}{\left\{{1\over f},f\right\}}
/endcode
$$
\xhbigcup{}{f\in L^2(\mu),\int f>0}\left\{{1\over f},f\right\};\qquad
\xvbigcup{}{f\in L^2(\mu),\int f>0}{\left\{{1\over f},f\right\}};\qquad
\xhvbigcup{}{f\in L^2(\mu),\int f>0}{\left\{{1\over f},f\right\}}
$$
\emacroexp

\macroexp{\xhbigcap {<sup>}{<sub>}/crcr
\xvbigcap {<sup>}{<sub>}{<material>}/crcr
\xhvbigcap {<sup>}{<sub>}{<material>}}
\blist
    \item \macro\xhbigcap{} paints a big-cap symbol stretched horizontally to match the width of its limits;
    \item \macro\xvbigcap{} paints a big-cap symbol stretched vertically to match the height and depth of
        {\it material} with the specified limits;
    \item \macro\xhvbigcap{} paints a big-cap symbol stretched both horizontally (to match the width of its
        limits) and vertically (to match the height and depth of {\it material}).
\elist
For example,
\begincode
\xhbigcap{}{n=1,2,3,\dots}\left[0,{1\over n}\right]
\xvbigcap{}{n=1,2,3,\dots}{\left[0,{1\over n}\right]}
\xhvbigcap{}{n=1,2,3,\dots}{\left[0,{1\over n}\right]}
/endcode
$$
\xhbigcap{}{n=1,2,3,\dots}\left[0,{1\over n}\right];\qquad
\xvbigcap{}{n=1,2,3,\dots}{\left[0,{1\over n}\right]};\qquad
\xhvbigcap{}{n=1,2,3,\dots}{\left[0,{1\over n}\right]}
$$
\emacroexp

\macroexp{\xhprod {<sup>}{<sub>}/crcr
\xvprod {<sup>}{<sub>}{<material>}/crcr
\xhvprod {<sup>}{<sub>}{<material>}}
\blist
    \item \macro\xhprod{} paints a product symbol stretched horizontally to match the width of its limits;
    \item \macro\xvprod{} paints a productsymbol stretched vertically to match the height and depth of
        {\it material} with the specified limits;
    \item \macro\xhvprod{} paints a product symbol stretched both horizontally (to match the width of its
        limits) and vertically (to match the height and depth of {\it material}).
\elist
For example,
\begincode
\xhprod{}{n=1,2,3,\dots}\left[0,{1\over n}\right]
\xvprod{}{n=1,2,3,\dots}{\left[0,{1\over n}\right]}
\xhvprod{}{n=1,2,3,\dots}{\left[0,{1\over n}\right]}
/endcode
$$
\xhprod{}{n=1,2,3,\dots}\left[0,{1\over n}\right];\qquad
\xvprod{}{n=1,2,3,\dots}{\left[0,{1\over n}\right]};\qquad
\xhvprod{}{n=1,2,3,\dots}{\left[0,{1\over n}\right]}
$$
\emacroexp

\subsection{Stretchy Logo}

Stretchy also provides macros for producing its logo.
To produce the logo itself, Stretchy provides the macro \macro\stretchylogo:

\centerline{\stretchylogo}

To produce the e and t in the Stretchy logo, Stretchy provides the macros \macro\strty@e{} and
\macro\strty@t, whose usages are

\getmacrousage{\strty@e {<width>}/crcr\strty@t {<width>}{<height+depth>}}

For example,

\begincode
\strty@e{15pt}
\strty@t{15pt}{10pt}
/endcode

\centerline{\strty@e{15pt}\qquad\strty@t{15pt}{10pt}}