SgpDec: Hierarchical Composition and Decomposition of Permutation Groups and Transformation Semigroups

What is it good for?

Understanding the structure of finite computations. In the long run, it is meant to be game changing in artificial intelligence, systems biology, physics, or in any field where models with discrete states make sense.

For a lightweight popular science style reading on computational semigroup theory check the Compsemi blog.

How to get it?

You need the latest version of the GAP computer algebra system

The released archives can be downloaded from the sourceforge hosting site, released files.

Most users just clone the repository from, the tip might be broken but version number tags are safe to update to.

How to use it?

To get some idea what SgpDec is capable of, check this paper: SgpDec: Cascade (De)Compositions of Finite Transformation Semigroups and Permutation Groups. For further details the documentation should be helpful.

Where to complain when something goes wrong?

Please report any problem or request features by creating on issue on the project page here.

Who are you?

Attila Egri-Nagy

James D. Mitchell

Chrystopher L. Nehaniv