1. Functorial polymorphism;Bainbridge;Theoret. Comput. Sci.,1990
2. Dinaturality for free;Freyd,1992
3. Functorial parametricity;Freyd,1992
4. Normal forms and cut-free proofs as natural transformations;Girard,1991
5. Algebraic types in PER models;Hyland,1990