The lambda calculus was invented by Church in the late 1920s, as part of an ambitious project to build a foundation for mathematics around the concept of function. Although his original system turned out to be logically inconsistent, Church was able to extract from it two separate usable systems that remain of great interest to this day, with a typed calculus for logic and an untyped calculus for pure computation. In the talk, I will survey some surprising connections discovered over recent years between linear subsystems of lambda calculus and enumeration of graphs on surfaces, or « maps », which is an active subfield of combinatorics with roots in W. T. Tutte’s work in the 1960s. Part of the interest in these links is that they suggest we may be able to develop new logical perspectives on maps and related combinatorial objects, and at the same time new quantitative perspectives on lambda calculus and related systems.
Seminar room 4B125 (Copernic building)
5 Boulevard Descartes 77420 Champs-sur-Marne