source code limits

Before trying to discover the details by myself, I was wondering whether someone
has an idea of the actual limits concerning the following aspects of Prolog
input files (ours are automatically generated by a translator; we try to attack
fd optimization problems with thousands of boolean variables and constraints):

- maximal size of list literals ([a,b,c,d...])
- maximal number of goals in a rule body
- maximal number variables appearing in a rule
- maximal number of fd variables
- maximal size of expressions inside constraints (3*A+4*B+2*C+...#<Z)
- maximal number of constraints
- maximal arity of a term

I bet those limits correspond to some constants/macros in the sources of
gprolog; it would be great to point us to the right place, so that we can adapt
and rebuild our own version.

Thanks in advance.