Types for Proofs and Programs International Workshop, TYPES'99, Lökeberg, Sweden, June 12-16, 1999, Selected Papers - Coquand, Thierry; Coquand, Thierry; Dybjer, Peter; Dybjer, Peter; Nordström, Bengt; Nordström, Bengt; Smith, Jan; Smith, Jan (Springer Berlin Heidelberg : Imprint: Springer, 2000)