 Růžička's proof follows the main lines of Wehrung's proof, except that it introduces an enhancement of Kuratowski's Free Set Theorem, called there "existence of free trees", which it uses in the final argument involving the Erosion Lemma.The proof of the negative solution for CLP shows that the problem of representing distributive semilattices by compact congruences of lattices already appears for congruence lattices of "semilattices".The question whether the structure of partially ordered set would cause similar problems is answered by the following result.