A Matita to Dedukti translator

What is Krajono?

Krajono (which means pencil in Esperanto) translates the proofs of Matita to the Dedukti logical framework. The translation is based on the works of Cousineau and Dowek [1] for pure type systems, Boespflug and Burel [2] for inductive types, and Assaf [3] for the infinite universe hierarchies and cumulativity.


  1. D. Cousineau and G. Dowek, Embedding pure type systems in the lambda-Pi calculus modulo, TLCA 2007
  2. M. Boespflug and G. Burel, Coqine: Translating the calculus of inductive constructions into the lambda-Pi calculus modulo, PXTP 2012
  3. A. Assaf, A calculus of constructions with explicit subtyping, submitted to the post- proceedings of TYPES 2014

Code and license

The current prototype is implemented as a fork of matitac (based on the 2014/11/24 svn snapshot). The code is distributed under the CeCILL free software license (the French equivalent of the GNU GPL). It can be downloaded here or directly from the Inria Forge project page.


Krajono is a fork of Matita that adds an option to export proofs to Dedukti. You compile it just like you compile matita. See Matita’s (complicated) compilation process for further info. Good luck! ;-)

To use Krajono, call matitac with the -extract_dedukti option on your matita (.ma) file:

matitac -extract_dedukti lib/arithmetics/

Because of the way Matita caches developments, this option forces the recompilation of the file. At the end, the translation produces one dedukti (.dk) file for each matita file that contains at least one object. It produces nothing for empty (e.g. wrapper) files. It also produces a file that contains the definitions of the universes used by these files. All the files depend on the file in the present directory.

The included Makefile can be used to translate (make translate) and check (make check) parts of the Matita library. Currently, the arithmetics library is translated and successfully checked with little modification. Additionally, there are two scripts and that can collect various data from the output of the translation and verification passes of the build process and display them in a clean and concise way that can serve to compile benchmarks.

Known problems


Krajono is developed and maintained by Ali Assaf. For information, feedback, bugs, and everything else, please contact him at at