canonical ordering

[Garnet Kin-Lic Chan]

Hi,

I have been extending GiNaC in various ways, but something I haven't yet
fathomed is the canonical ordering that automatically happens. For
example, I derived a class from indexed, whose compare_same_type simply
calls the inherited::compare_same_type, yet the ordering of products in my
class was different from that of the usual indexed objects. What
determines and triggers the canonical ordering? Perhaps this could also be
explained somewhere in the reference.

sincerely,

Garnet