// Here we return true only if x is the *exact* zero. Because we
// don't want the degree of polynomials to depend on rounding errors.
// For all ring theoretic purposes, we treat 0.0 as if it were a
// Here we return true only if x is the *exact* zero. Because we
// don't want the degree of polynomials to depend on rounding errors.
// For all ring theoretic purposes, we treat 0.0 as if it were a