We have planned, tentatively, three visits of the Brazilian group to Berlin, including two visits of 1-3 months of the researchers and one visit of 2-6 months of a PhD student. For the German group we plan to have three visits of 1-3 months of the researchers and one visit of 2-6 months of a PhD student to São Paulo. There will be one visit per semester, alternatively, beginning in the second semester of 1994 (September/October) with a visit of a German partner.