A lattice for which the least upper bouNd (lub) aNd greatest lower bouNd (glb) operators distribute over oNe aNother so that a lub (b glb c) == (a lub c) glb (a lub b) aNd vice versa. ("lub" aNd "glb" are writteN iNLateX as sqcup aNd sqcap). (1998-11-09)