Toposes Algebraic Geometry and Logic : Dalhousie University Halifax January 16–19 1971 Sheaf theory and the continuum hypothesis Classifying topos Deductive systems and categories III. Cartesian closed categories intuitionist propositional calculus and combinatory logic The formalization of Bishops constructive mathematics Continuous lattices Some applications of the formalism of duality in algebraic geometry Cotangent complex and deformations of torsors and group schemes.