Function antichain_insert

src/transform/src/analysis.rs:747–753

(into: &mut Vec<Vec<usize>>, item: Vec<usize>)

    }

    fn antichain_insert(into: &mut Vec<Vec<usize>>, item: Vec<usize>) {
        // Insert only if there is not a dominating element of `into`.
        if into.iter().all(|key| !key.iter().all(|k| item.contains(k))) {
            into.retain(|key| !key.iter().all(|k| item.contains(k)));
            into.push(item);
        }
    }

    /// Lattice for sets of columns that define a unique key.
    ///