I quite agree. If you're trying to do numerical integration in Perl (and if your trying to do quite a number of other things), _Mastering Algorithms with Perl_ is a great book.

However, doing algebraic integration is rather beyond it's scope. It is, in fact, quite difficult. To quote:

If it's symbolic computation you're looking for, this chapter won't help -- but Ulrich Pfeifer's Math::ematica module will. Ulrich's module is freely available from CPAN, but requires the not-free Mathematica package to operate. There are, unfortunately, no free symbolic math packages available for Perl. Yet.

PS: Please excuse my terrible spelling.