\begin{center}\begin{minipage}{15cm}\begin{Verbatim}[frame=single]
> restart;
The tool has been restarted.
> a.f = exp(x);
> a.dom = [-1;1];
> a.info.text = "My akrnoximation problem";
> a;
{ .info = { .text = "My akrnoximation problem" }, .dom = [-1;1], .f = exp(x) }
> 
> a.info.text = "My approximation problem";
> a;
{ .info = { .text = "My approximation problem" }, .dom = [-1;1], .f = exp(x) }
> 
> b = exp(x);
> b.a = 5;
Warning: cannot modify an element of something that is not a structure.
Warning: the last assignment will have no effect.
> b;
exp(x)
> 
> a.dom.a = -1;
Warning: cannot modify an element of something that is not a structure.
Warning: the last assignment will have no effect.
> a;
{ .info = { .text = "My approximation problem" }, .dom = [-1;1], .f = exp(x) }
\end{Verbatim}
\end{minipage}\end{center}
