> > OK, let's try with a being the imaginary unity. > I thought that by default FriCAS assumes that variables are real.
> Because it is just an operator and a can be anything. Fair enough. Then one should be able to specify on which domain an operator is acting and abs(a) | a is real should know that a > 0. I just found out that the exact same question was asked 7 years ago: https://groups.google.com/d/topic/fricas-devel/jTeaKzcEJgs/discussion It is surprising that nothing has been done to correct this problem. But reading that thread explains why. It is not a matter of mathematics or computer science, but a matter of sociology. To us physicists, Juanjo in that thread and myself, a CAS should be a tool that helps us save time by performing the calculations that come up in our work. But to the current maintainers of the big three: Maxima, FriCAS and Reduce, it does not matter that their programs cannot calculate Gaussian integrals (all three have failed my tests). In the Axiom/FriCAS wiki it is claimed that this CAS boasts the most complete implementation of the Risch algorithm. And I am sure that it can calculate thousands of integrals. But what is the purpose of having a sophisticated integrator if it cannot calculate the simplest integrals? In the thread above Waldek replies: do not use it for calculating integrals you already know. Seriously? I must say that it is highly disappointing that to this date there is no serious free-software alternative to Mathematica. The three programs mentioned above have been developed for about 40-50 years by very capable computer scientists and mathematicians. Axiom/FriCAS is IMHO the best designed of the three, it is thoroughly documented and all that effort is wasted because the developers do not care for the needs of the users. Pretty sad. Marduk -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
