Function: bnrrootnumber
Section: number_fields
C-Name: bnrrootnumber
Prototype: GGD0,L,p
Help: bnrrootnumber(bnr,chi,{flag=0}); returns the so-called Artin Root
 Number, i.e. the constant W appearing in the functional equation of the
 Hecke L-function associated to chi. Set flag = 1 if the character is known
 to be primitive

