This should be again due to the difference between 1.3 and 1.4 branches.
I'll will install CVS version to follow. It was my mistake letting the varidx to have dimension 3, as you say they must be of dimension 2. Mean while, I see that geometric products of type e~1*e~1 are being simplified to ONE, that I suppose that can be removed using ex remove_dirac_ONE(const ex & e) Also I see in a0+(e~0*e~1)*a3+e~1*a2+a1*e~0 that e~1*e~0 expresions are outputed like (e~0*e~1). (e~0*e~1) stands for a GiNaC's symbol (single 2-blade) or a product of two GiNaC's symbols (product of two 1-blades). If I want to trigger specific simplifications for the Cl2 geometric algebra, like (e~1*e~0)=-(e~0*e~1) or e~0*(e~0*e~1)=e~1 e~0*e~1*e~0*e~1=-1 I suppose that I will have to do them myself using ().subs(), don't I? Thanks again, it has been very helpfull. Javier