Function: rnfequation
Section: number_fields
C-Name: rnfequation0
Prototype: GGD0,L,
Help: rnfequation(nf,pol,{flag=0}): given a pol with coefficients in nf,
 gives the absolute equation apol of the number field defined by pol. flag is
 optional, and can be 0: default, or non-zero, gives [apol,th], where th
 expresses the root of nf.pol in terms of the root of apol

