Tex sample rsfs

Using the "rsfs" Fonts in plain TeX

Ralph Smith's Formal Script is a script font that is more elaborate than the "calligraphic" font obtained by \Cal. Like \Cal, though, it includes capital letters only.

% the following implements the rsfs fonts
\font\tenscr=rsfs10
\font\sevenscr=rsfs7
\font\fivescr=rsfs5
\skewchar\tenscr='177 \skewchar\sevenscr='177 \skewchar\fivescr='177
\newfam\scrfam \textfont\scrfam=\tenscr \scriptfont\scrfam=\sevenscr
\scriptscriptfont\scrfam=\fivescr
\def\scr#1{{\fam\scrfam#1}}

Let $\scr F$ be a sheaf.  Call it $\scr G$.
\bye

(Note that this is not to be taken as an example of good mathematical exposition.)