bnrmap

bnf = bnfinit(x^2-x-57);
bnr = bnrinit(bnf, [5,[1,1]]);
chi = [12,2];
m = bnrconductor(bnr,[12,2]);
bnr2 = bnrinit(bnf,m);
S = bnrmap(bnr, bnr2)
bnrmap(S, chi)
bnrmap(S, charker(bnr,chi))
bnrmap(S, 2)
bnrmap(S,[1,2]~)
apply(x->bnrmap(S,x), subgrouplist(bnr.cyc))

\\ ERRORS
bnrmap(1,2)
bnrmap(bnr, bnrinit(x,1))
bnrmap(S,[1,2,3])
bnrmap(S,[1,2]/2)
bnrmap(S,[1,2,3]~)
bnrmap(S,[1,2]~/2)
bnrmap(S,matid(3))
bnrmap(S,matid(2)/2)