Special linear group:SL(2,9)

Definition
This group is defined in the following equivalent ways:


 * 1) It is the member of family::special linear group of degree two over the field of nine elements.
 * 2) It is the group $$2 \cdot A_6$$, or equivalently, a double cover of alternating group:A6. In other words, it is a stem extension where the base normal subgroup is cyclic group:Z2 and the quotient group is defining ingredient::alternating group:A6. Because $$A_6$$ is a perfect group, it is the unique stem extension of this sort. Thus, it belongs to the family member of family::double cover of alternating group.