A distributive lattice is a lattice in which join and meet distribute over each other, in that for all in the latiice, the distributivity laws are satisfied:
The nullary forms of distributivity follow automatically:
Distributive lattices and lattice homomorphisms form a concrete category DistLat.
Any lattice that satisfies one of the two binary distributivity laws must also satisfy the other; isn't that nice? This convenience does not extend to infintary distributivity, however.
Any Boolean algebra, and even any Heyting algebra, is a distributive lattice.
Every distributive lattice, regarded as a category (a (0,1)-category), is a coherent category.
Conversely, the notion of coherent category may be understood as a categorification of the notion of distributive lattices.
The completely distributive algebraic lattices (the frames of opens of Alexandroff locales ) form a reflective subcategory of that of all distributive lattices. The reflector is called canonical extension.