## Section: Software

### Ott: tool support for the working semanticist

Participant : Francesco Zappa Nardelli [contact] .

Languages, semantics, tool support, theorem prouvers.

Ott is a tool for writing definitions of programming languages and calculi. It takes as input a definition of a language syntax and semantics, in a concise and readable ASCII notation that is close to what one would write in informal mathematics. It generates output:

Additionally, it can be run as a filter, taking a LaTeX/Coq/Isabelle/HOL source file with embedded (symbolic) terms of the defined language, parsing them and replacing them by typeset terms.

The main goal of the Ott tool is to support work on large programming language definitions, where the scale makes it hard to keep a definition internally consistent, and to keep a tight correspondence between a definition and implementations. We also wish to ease rapid prototyping work with smaller calculi, and to make it easier to exchange definitions and definition fragments between groups. The theorem-prover backends should enable a smooth transition between use of informal and formal mathematics.

In collaboration with Peter Sewell (Cambridge University).

The current version of Ott is about 30000 lines of OCaml. The tool is available from http://moscova.inria.fr/~zappa/software/ott (BSD licence). It is widely used in the scientific community.

In 2012 we implemented several bug-fixes and we kept the theorem prouver backends up-to date with the prover evolution. We have also been working toward a closer integration with the Lem tool.

The currently relased version is 0.21.2.