// processMonomialProduct
// m is a monomial, component is ignored (it determined the possible n's
// being used here)
// n is a monomial at level 'mThisLevel-1'
// compute their product, and return the column index of this product
// or -1, if the monomial is not needed.
// additionally: the product monomial is inserted into the hash table
// and column array (if it is not already there).
// caveats: this function is only to be used during construction
// of the coeff matrices. It uses mThisLevel.
//
// If the ring has skew commuting variables, then result_sign_if_skew is set to
// 0, 1, or -1.
ComponentIndex F4Res::processMonomialProduct(res_const_packed_monomial m,
res_const_packed_monomial n,
int& result_sign_if_skew)
{
result_sign_if_skew = 1;
auto x = monoid().get_component(n);
auto& p = mFrame.level(mThisLevel - 2)[x];
if (p.mBegin == p.mEnd) return -1;
int* thisMonom = mMonomSpace2.allocate(1 + monoid().max_monomial_size());
thisMonom++; // so thisMonom[-1] exists, but is not part of the monomial, as far as
monoid().unchecked_mult(m, n, thisMonom);
monoid().set_component(x, thisMonom);
if (ring().isSkewCommutative())
{
result_sign_if_skew = monoid().skew_mult_sign(ring().skewInfo(), m, n);
if (result_sign_if_skew == 0)
{
mMonomSpace2.popLastAlloc(thisMonom-1); // we did not need this monomial!
return -1;
}
}
return processCurrentMonomial(thisMonom);
}
// processMonomialProduct
// m is a monomial, component is ignored (it determined the possible n's being used here)
// n is a monomial at level 'mThisLevel-1'
// compute their product, and return the column index of this product
// or -1, if the monomial is not needed.
// additionally: the product monomial is inserted into the hash table
// and column array (if it is not already there).
// caveats: this function is only to be used during construction
// of the coeff matrices. It uses mThisLevel.
//
// If the ring has skew commuting variables, then result_sign_if_skew is set to 0, 1, or -1.
ComponentIndex F4Res::processMonomialProduct(packed_monomial m, packed_monomial n, int& result_sign_if_skew)
{
result_sign_if_skew = 1;
auto x = monoid().get_component(n);
auto& p = mFrame.level(mThisLevel-2)[x];
if (p.mBegin == p.mEnd) return -1;
monoid().unchecked_mult(m,n,mNextMonom);
// the component is wrong, after this operation, as it adds components
// So fix that:
monoid().set_component(x, mNextMonom);
if (ring().isSkewCommutative())
{
result_sign_if_skew = monoid().skew_mult_sign(ring().skewInfo(), m, n);
if (result_sign_if_skew == 0)
return -1;
}
return processCurrentMonomial();
}
