Conference Summary

Abstract

At the end of a meeting probably every participant has a tendency to go once more through the main topics discussed, asking himself the question in which areas major progress has been achieved, and which problems look most promising for future research. In my attempt to give you a balanced summary of this conference I intend to do the same. I will, however, change the sequence of the talks, combining those subjects which are most closely related, a step quite appropriate in the context of a summary.