arb/dirichlet/char_lift.c

36 lines
968 B
C

/*
Copyright (C) 2016 Pascal Molin
This file is part of Arb.
Arb is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "dirichlet.h"
void
dirichlet_char_lift(dirichlet_char_t y, const dirichlet_group_t G, const dirichlet_char_t x, const dirichlet_group_t H)
{
slong k, l;
if (G->q % H->q != 0)
{
flint_printf("conrey_lift: lower modulus %wu does not divide %wu\n", H->q, G->q);
abort();
}
for (k = 0, l = 0; k < G->num && l < H->num; k++)
{
if (G->P[k].p == H->P[l].p)
{
slong e = n_pow(G->P[k].p, G->P[k].e - H->P[l].e);
y->log[k] = x->log[l] * e;
l++;
}
}
_dirichlet_char_exp(y, G);
}