The Conference was organized by the Institute of Information Theory and Automation of the Czechoslovak Academy of Sciences from July 7 - 11, 1986, in Prague. The round number of the conference was only one of the jubilees connected with its organization. Namely, thirty years of the Prague Conferences (the first one was organized in autumn 1956 in Liblice near Prague), and two anniversaries of Professor Anton1n Spacek, the inspirator and first organizer of the Prague Conferences - 75 years of his birth and 25 years of his untimely death. (More about Professor Spacek can be found in the...