Some integrals with problematic evaluation

[parisse]

6000 rules, that's a lot!
About step by step in Xcas, it is at this time experimental, like the online interface : the idea is to provide a full javascript CAS engine (no need to have a server behind once the engine has been downloaded) + interface available on all devices that have a browser, and also enable the CAS engine in LaTeX files compiled to HTML5 (by hevea), so that students can perform computations or modify examples and see the results while reading an online course.