## Section: New Software and Platforms

### Other software developments

In collaboration with François Pottier (Inria Gallium), Yann Régis-Gianas maintained Menhir, an LR parser generator for OCaml.

Yann Régis-Gianas has been developing the “Hacking Dojo”, with the help of Alexandre Ly (master student of Paris Diderot). a web platform to automatically grade programming exercises. The platform is now used in several courses of the University Paris Diderot.

In collaboration with Grégoire Duchêne (master student at Paris Diderot), Yann Régis-Gianas developed Tamasheq, a fully-customisable interpreter for the OCaml programming language. Users of this interpreter can write plugins to instrument the interpretation of an OCaml program with visualisation, interactive debugging or logging. A paper is in preparation.

Yves Guiraud has updated the Catex tool for Latex, whose purpose is to automate the production of string diagrams from algebraic expressions (http://www.pps.univ-paris-diderot.fr/~guiraud/catex/catex.zip ).

Yves Guiraud has developed the Python library Cox for the computation of coherent presentations of Artin monoids, after [18] (http://www.pps.univ-paris-diderot.fr/~guiraud/cox/cox.zip ).

Yves Guiraud collaborates with Samuel Mimram (LIX) to develop the prototype Rewr that implements the homotopical completion-reduction procedure of [6] (http://www.pps.univ-paris-diderot.fr/~smimram/rewr ).

Eric Finster has developed a new proof assistant, called Orchard, which aims to pursue the emerging connections between type theory and higher category theory by providing an environment in which to explicitly manipulate higher categorical diagrams using a notation based on a collection of shapes called opetopes. Opetopes have strong connections to concepts from computer science: they have a natural interpretation as a series of canonical indexed inductive types, and thus can be implemented and reasoned about using standard techniques from functional programming. The goal of the Orchard project is to forge links between the homotopical ideas of homotopy type theory, and the higher categorical ideas coming from higher-dimensional rewriting theory by providing a common language in which to reason about both. A preliminary implementation is available at https://github.com/ericfinster/orchard .