In this post I shall discuss the paper “On a Topological Topos” by Peter Johnstone. The basic problem is that algebraic topology needs a “convenient category of spaces” in which to work: the category ...

Here, we revisit Ramanujan’s original definition from his deathbed letter (1, p 221). After a discussion of the asymptotics of certain modular forms, which are given as Eulerian series, he writes: ...

This blog entry is an excuse for continuing our discussion of cartesian closed categories (CCCs) and the λ-calculus in a slightly more organized way. Let’s focus on more or less “traditional” aspects ...