Function check_ns_lower_bound_gfp 

pub fn check_ns_lower_bound_gfp(
    f: NsField,
    num_vars: usize,
    clauses: &[Vec<Lit>],
    degree: usize,
    witness: &[(Mono, u64)],
) -> bool

check_ns_lower_bound_polys_gfp for a CNF. An empty clause admits no lower bound at any degree.