
D.8.6.7 factorMain
Procedure from library zeroset.lib (see zeroset_lib).
 Usage:
 factorMain(f); where f is a polynomial
 Purpose:
 compute the factorization of the squarefree polynomial f over Q(a)[t],
minpoly = p(a).
 Return:
 list with 2 entries
 _[1] = factors, first is a constant
_[2] = multiplicities (not yet implemented)

 Assume:
 basering = Q[x,a], representing Q(a)[x]. An ideal mpoly must
be defined, representing the minimal polynomial (it might be 0!).
 Note:
 outdated, use factorize instead
