A uniform space ("X", Θ) is a set "X" equipped with a distinguished family of coverings Θ, called "uniform covers", drawn from the set of coverings of "X", that form a filter when ordered by star refinement. One says that a cover P is a "star refinement" of cover Q, written P <* Q, if for every "A" ∈ P, there is a "U" ∈ Q such that if "A" ∩ "B" ≠ ø, "B" ∈ P, then "B" ⊆ "U". Axiomatically, the condition of being a filter reduces to: