\begin{center}\begin{minipage}{15cm}\begin{Verbatim}[frame=single]
> a = { .f = exp(x), .a = -1, .b = 1 };
> a;
{ .f = exp(x), .a = -1, .b = 1 }
> a.info = "My function";
> a;
{ .info = "My function", .f = exp(x), .a = -1, .b = 1 }
> 
> b = { .a = -1, .f = exp(x), .info = "My function", .b = 1 };
> b;
{ .a = -1, .f = exp(x), .info = "My function", .b = 1 }
> 
> a == b;
true
> 
> b.info = "My other function";
> a == b;
false
> 
> b.info = "My function";
> a == b;
true
> b.something = true;
> a == b;
false
\end{Verbatim}
\end{minipage}\end{center}
