Function check_subsumption 

pub fn check_subsumption(
    cached_predicate: Option<&Expression>,
    new_predicate: Option<&Expression>,
) -> SubsumptionResult

Check if new_predicate is subsumed by cached_predicate

Returns:

• Identical if predicates are semantically equivalent
• Subsumed { filter } if new_predicate is stricter than cached_predicate
• NoSubsumption if we can’t determine a subsumption relationship