#include "fmpz_mod.h"
#include "fmpz_mod_poly.h"
void fmpz_mod_poly_sub_series(fmpz_mod_poly_t res, const fmpz_mod_poly_t poly1,
const fmpz_mod_poly_t poly2, slong n, const fmpz_mod_ctx_t ctx)
{
slong len1, len2, max = FLINT_MAX(poly1->length, poly2->length);
if (n < 0)
n = 0;
max = FLINT_MIN(max, n);
len1 = FLINT_MIN(poly1->length, max);
len2 = FLINT_MIN(poly2->length, max);
fmpz_mod_poly_fit_length(res, max, ctx);
_fmpz_mod_poly_sub(res->coeffs, poly1->coeffs, len1, poly2->coeffs, len2, ctx);
_fmpz_mod_poly_set_length(res, max);
_fmpz_mod_poly_normalise(res);
}