 Every finite distributive lattice is isomorphic to the congruence lattice of some finite lattice.It is important to observe that the solution lattice found in Grätzer and Schmidt's proof is "sectionally complemented", that is, it has a least element (true for any finite lattice) and for all elements "a" ≤ "b" there exists an element "x" with "a" ∨ "x" = "b" and "a" ∧ "x" = "0".It is also in that paper that CLP is first stated in published form, although it seems that the earliest attempts at CLP were made by Dilworth himself.