Bogusław Wolniewicz, inspired by his formal ontology of situations, has
put forward a question on semilattices with a unit (*A question about
joinsemilattices*, Bulletin of the Section of Logic 19/3, 1990). The
present paper is entirely devoted to this problem in the formulation
given by Wolniewicz. First, the meaning of the question is analyzed and
its lattice-theoretical and Boolean algebraic contents are exhibited.
Second, set-theoretical and topological counterparts of the question are
formulated and commented upon.