6.1 What doesn't belong into GiNaC

First of all, GiNaC's name must be read literally. It is designed to be a library for use within C++. The tiny ginsh accompanying GiNaC makes this even more clear: it doesn't even attempt to provide a language. There are no loops or conditional expressions in ginsh, it is merely a window into the library for the programmer to test stuff (or to show off). Still, the design of a complete CAS with a language of its own, graphical capabilities and all this on top of GiNaC is possible and is without doubt a nice project for the future.

There are many built-in functions in GiNaC that do not know how to evaluate themselves numerically to a precision declared at runtime (using Digits). Some may be evaluated at certain points, but not generally. This ought to be fixed. However, doing numerical computations with GiNaC's quite abstract classes is doomed to be inefficient. For this purpose, the underlying foundation classes provided by CLN are much better suited.