.. _ch:arithgroup:
Arithmetic Subgroups of `{\rm SL}_2(\ZZ)`
================================================
This chapter describes the basic functionality for finite index subgroups of
the modular group `{\rm SL}_2(\ZZ)`.
.. toctree::
:maxdepth: 2
sage/modular/arithgroup/arithgroup_generic
sage/modular/arithgroup/arithgroup_perm
sage/modular/arithgroup/arithgroup_element
sage/modular/arithgroup/congroup_generic
sage/modular/arithgroup/congroup_gammaH
sage/modular/arithgroup/congroup_gamma1
sage/modular/arithgroup/congroup_gamma0
sage/modular/arithgroup/congroup_gamma
sage/modular/arithgroup/congroup_sl2z
sage/modular/arithgroup/farey_symbol
