Lazier Binary Decision Diagrams (BDDs) for set-theoretic types

The Elixir team and the CNRS are working on a set-theoretic type system for Elixir which, simply put, is a type-system powered by unions, intersections, and negations. As part of the implementation of said type systems, we need an efficient way of representing said operations. This article discusses the existing approaches found in theory and practice, as well as the improvements we have introduced as part of Elixir v1.19 . This article covers the implementation details of the type system. You don’t need to