PRELIMINARY ANNOUNCEMENT The Federated Conference Mathematical Foundations of Computer Science and Computer Science Logic will take place in Brno (Czech Republic) during August 23-28, 1998. In this connection, I am going to hold the meeting of the Peripatetic Seminar on Sheaves and Logic in Brno over the weekend of August 29-30, 1998. As usual, there will be welcomed talks on category theory, sheaves, logic and related areas (theoretical computer science in particular). Jiri Rosicky