This mode is a port of Helena A. Verrill's Fundamental Domain Drawer (Java applet, 2001): the choice of groups, the walk that lays out the triangles, the side-pairing table, the edit and link modes and the triangle explorer are hers, following her Algorithm for Drawing Fundamental Domains (January 2001).
Click a triangle for its matrix. In edit mode, click a yellow marker to redraw the triangle paired with that side there.
Algorithm and original applet: Helena A. Verrill, Algorithm for Drawing Fundamental Domains, January 2001. Tables: C. Cummins and S. Pauli. Congruence test: T. Hsu, Proc. AMS 124 (1996).
| Name | \(\Gamma\) |
| Index | 1 |
| con | 1 |
| len | 1 |
| c₂ | 1 |
| c₃ | 1 |
| Cusps | \(1^{1}\) |
| Gal | \(1^{1}\) |
| Supergroups | — |
| Subgroups | |
| Matrix generators | — |
An entry of the tables, up to conjugacy in PGL₂(ℤ); its name opens it there.
Click a triangle to see its matrix and its side pairings.