Partially ordered elements with a least upper bound.
Lattices form the basis of differential dataflow’s efficient execution in the presence of
iterative sub-computations. All logical times in differential dataflow must implement the
Lattice trait, and all reasoning in operators are done it terms of
A bounded partially ordered type supporting joins and meets.
Returns the “smallest” minimal antichain “greater or equal” to both inputs.
Returns the “greatest” minimal antichain “less or equal” to both inputs.