Short answer is that ?g1234 etc are so-called gensyms,
that is, generated Lisp symbols.
Looks like ?g1811 is a dummy variable in the Laplace transform.
On the face of it, it looks correct, but desolve could
pick a less confusing name.
best
Robert Dodier
On 3/14/11, Karl-Dieter Crisman <kcrisman at gmail.com> wrote:
> I know that sometimes in the solving code (esp. Barton's stuff) we can
> get temporary integer or real or whatever variables that look like i3
> or r55.
>
> But what the heck are the g things here? This comes from Sage ticket
> http://trac.sagemath.org/sage_trac/ticket/9825
>
> x1(t)=ilt(-((3*laplace(x2(t)^2,t,?g1811)-x1(0))*?g1811-3)/?g1811^2,?g1811,t)
>
> This comes from a desolve command, but tracking down exactly what Sage
> has sent to Maxima to get this would be tedious. Needless to say,
> trying to search the manuals for this wasn't so helpful, e.g.
> http://maxima.sourceforge.net/docs/manual/en/maxima_22.html has
> examples that work, not ones that don't.
>
> But we'd be grateful for the help so we can properly parse Maxima
> answers even more accurately. Thanks!
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