TOPICS Algebra Applied Mathematics Calculus and Analysis Discrete Mathematics Foundations of Mathematics Geometry History and Terminology Number Theory Probability and Statistics Recreational Mathematics Topology Alphabetical Index New in MathWorld Foundations of Mathematics Set Theory Set Properties Bijective Boolean Representation Theorem Consistency Theorem Greatest Lower Bound Infimum Infimum Limit Kneser's Conjecture Least Upper Bound Nowhere Dense Operation Poretsky's Law Rank Set Span Supremum