Function: rnfnormgroup
Section: number_fields
C-Name: rnfnormgroup
Prototype: GG
Help: rnfnormgroup(bnr,polrel): norm group (or Artin or Takagi group)
 corresponding to the Abelian extension of bnr.bnf defined by polrel, where
 the module corresponding to bnr is assumed to be a multiple of the
 conductor. The result is the HNF defining the norm group on the given
 generators in bnr[5][3]

