Dear developers, I have been using the Ginac library for some of my hobby programs now and I believe a generic C++ CAS would be very valuable. I have grown interest in symbolic integration and tried implementing polynomial factorization, it seems quite hard to do efficiently, but doable. I have even bought the book mentioned in the todo list (the second edition). Altough I have just began to read it the book mentions that some recent algorithms for trancedental integration do not require polynomial factorization. So I would like to try and implement one of these algo's. My question is, what are your thoughts on how to implement integration in a nice fashion? I tought about implementing some kind of antiderivative operator wich can be used in expressions and gives the indefinite integral. The reason I preffer operators to member function is that it allows unsolvable integrals to remain in the equation and still be numerically evaluable. In this fashion I would like to create a differential operator so ODE's and PDE's can be expressed in Ginac and numerically solved. The hobby program I am trying to make should become a generic numerical integrator for arbitrary PDE's by dynamicaly generating code. I already have a class that converts an expression to its Chebyshev-Pade approximation, compiles it to double arithmetic and dynamicly links it in. So gentleman, what are your thoughts? Sincerely, R. Bloemen