Function generalized_candidate_wf 

pub open spec fn generalized_candidate_wf<const DER: bool>(
    bytes: Seq<u8>,
    main_end: usize,
    zone_start: usize,
) -> bool

{
    &&& main_end <= zone_start <= bytes.len()
    &&& generalized_fields_wf(bytes, main_end)
    &&& generalized_fraction_wf::<DER>(bytes, main_end, zone_start)
    &&& generalized_zone_wf::<DER>(bytes, zone_start)

}