The Summer School will take place at Fortaleza, in Ceará, which is a state in the northeastern region of Brazil. Fortaleza is 2.800 km from Rio de Janeiro, 1.500 km from Brasilia and 5.000 km from Buenos Aires. Fortaleza has a great tourism infra-structure and good hotels, a pleasant weather and beautiful landscapes, which make it an ideal place for scientific exchange among the School's participants. The School will take place during two successives weeks of March 2001, namely, the 12th to the 16th and the 20th to the 24th. An international symposium on algorithms and combinatorics will take place during the weekend from the 17th to the 19th.