Function counter_abduction 

pub fn counter_abduction(
    candidates: &[u64],
    refuted: &[u64],
    out: &mut [u64],
) -> usize

Counter-abduction: from candidates, drop every hypothesis that has been refuted (ruled out by an observation, or contradicted by an established fact), writing the survivors into out. Returns the surviving count — aggressive pruning of contradictory hypotheses. Zero-heap.