ICFP 2011 The 16th ACM SIGPLAN International Conference on Functional Programming On the Bright Side of Type Classes: Instance Arguments in Agda Dominique Devriese and Frank Piessens (K.U.Leuven) Set-theoretic Foundation of Parametric Polymorphism and Subtyping Giuseppe Castagna (CNRS - Université Paris Diderot) and Zhiwu Xu (Université Paris Diderot and Institute of Software Chinese Academy of Sc