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Von: sen1 at math.msu.edu [mailto:sen1 at math.msu.edu]
> (%i15) assume(s>0);
> (%o15) [s > 0]
> (%i16) laplace(t^2*f(t),t,s);
>
> (%o16) 'diff(?%laplace(f(t),t,s),s,2)
> (%i17) facts();
> (%o17) [s > 0]
>
> Did you try this on 5.17.1 ?
No, I am using the last CVS. My example was not a good one, but it is possible
to reproduce the effect with other integrals with Maxinma 5.17.1 too.
> P.S. Dieter, Will you include the ability to take the inverse transforms
> of things like exp(-3*s)/x^2 ? That is, functions f(t) which involve
> step functions? It would be good if you can.
> Note: I worked out routines which do this in maxima (not lisp). If it
> would be useful to you, I can send them to you. They simply involve
> breaking up linear combination of 'monomials' which may or may not
> contain factors (exp(-c*s)) and dealing with each one separately. You
> may prefer (if you want to add this feature) to just do them yourself.
> My codes use some shortcuts for my convenience, so I would have to
> change them a bit for your use. If you want them, please let me know,
> and I'll make the changes and send them.
It would be a pleasure for me to get your code.
Dieter Kaiser