## Section: New Results

### Deriving equality tests

Participant : Enrico Tassi.

In type theory, for most inductive types, it is possible to construct a two-argument boolean function that tests when two terms of the type are equal. When inductive types have constructors containing sub-components from another inductive, this needs to be done in a modular way. This year, we studied how this problem could be solved in a modular way using Elpi. It turns out that the unary parametricity translation can serve as a tool to make the derivation compositional. This is described in a pre-print [25].