On groups of unit elements of certain quadratic forms. (English) Zbl 0252.20054
MSC:
20F05 | Generators, relations, and presentations of groups |
11E16 | General binary quadratic forms |
51M10 | Hyperbolic and elliptic geometries (general) and generalizations |
20H10 | Fuchsian groups and their generalizations (group-theoretic aspects) |