\frametitle {SAGE Demo:  Interfaces}
{\dred HOW THEY WORK:} Use buffered psuedo-tty, files,
and Python objects that wrap native objects.  This makes
it possible to wrap {\dred all} math software
that has a command line interface using
similar code.

\vfill
{\blue
\begin{verbatim}
sage: x = gp('9+6')    # the GP/PARI math software
\end{verbatim}}
This fires up one copy of GP/PARI (if it wasn't already started)
and sends the line {\tt 'sage[1] = 9+6'} to it.
It also creates a Python class x with a field set to {\tt "sage[1]"}.
{\small\blue \begin{verbatim}
sage: !ps ax |grep gp
16389  p5  Ss+    0:00.02 /Users/was/s/local/bin/gp --fast ...
sage: type(x)
<class 'sage.interfaces.gp.GpElement'>
sage: x
15
sage: x.name()
'sage[1]'
sage: x.factor()
[3, 1; 5, 1]
\end{verbatim}
}