2. M. Wester's CAS benchmark and Yacas

In his 1994 paper Review of CAS mathematical capabilities, Michael Wester has put forward 123 problems that a reasonable computer algebra system should be able to solve and tested the then current versions of various commercial CAS on this list.

Below is the list of Wester's problems with the corresponding Yacas code. "OK" means a satisfactory solution, "BUG" means that Yacas gives a wrong solution or breaks down, "NO" means that the relevant functionality is not yet implemented.

Yacas version: 1.2.2

Verify(Simplify(Integrate(x) Abs(x)),
  Abs(x)*x/2);