Finite-index subgroups of (P)SL(2,Integers)

Version 1.0.0
Released 2020-04-08

This project is maintained by Luca Leon Junk

GAP Package ModularGroup

This package provides a collection of algorithms for computing with finite-index subgroups of (P)SL(2,Z).

The current version of this package is version 1.0.0, released on 2020-04-08. For more information, please refer to the package manual. There is also a README file.


This package requires GAP version 4.5.3

The following other GAP packages are needed:

The following additional GAP packages are not required, but suggested:


This package was developed by

Luca Leon Junk. in the working group of Prof. Dr. Gabriela Weitze-Schmith├╝sen at Saarland University.


Please, cite this package as

[Jun20] Junk, L. L., ModularGroup, Finite-index subgroups of (P)SL(2,Integers), Version 1.0.0 (2020)
(GAP package),

You can get more info by typing Cite("ModularGroup"); in the gap prompt.


For bug reports, feature requests and suggestions, please use the issue tracker.