The ?rst International Summer School on Theoretical Aspects of Computer Science was organized by the Institute for Studies in Theoretical Physics and Mathematics(IPM)inTehran, Iran. ProgramCommittee ConferenceChair: G. B. Khosrovshahi, IPMandtheUniversity ofTehran, Iran A. Shokoufandeh, DrexelUniversity, USA A. Shokrollahi, DigitalFountain, USA Local Arrangements: M. Zamani SponsoringInstitutions SchoolofMathematics, Institutefor Studies in Theoretical Physics and Mathematics(IPM),Tehran, Iran World Mathematical Year (WMY) 2000 National Commission Service de Coop¿ eration et d¿ Action Culturelle, AmbassadedeFranceen Iran Neda Rayaneh Institute (NRI) http://www. neda. net. ir VIII Acknowledgements WearegratefultoProfessorM. J. Larijani,thedirectorofIPM,whohasbeen a great advocate for the expansion of Theoretical Computer Science at the - stitute,andhelpedussecuremajorfundingfromIPM. Wewouldalsoliketo expressourthankstoProfessorS. Shahshahani,theDeputyDirectorofIPM, who was most helpful in