Finitary formal topologies and Stone's representation theorem

We study the concept of finitary formal topology, a point-free version of a topological space with a basis of compact open subsets. The notion of finitary formal topology is defined from the perspective of the Basic Picture (introduced by the second author) and thus it is endowed with a binary positivity relation. As an application, we prove a constructive version of Stone’s representation theorem for distributive lattices. We work within the framework of aminimalist foundation (as proposed byMaria EmiliaMaietti and the second author). Both inductive and co-inductive methods are used in most proofs. © 2008 Elsevier B.V. All rights reserved.