/*
www-ATLAS of Group Representations.
3.L3(4):2a represented as 21 x 21 matrices over GF(25).
*/

F<w>:=GF(25);

x:=CambridgeMatrix(3,F,21,\[
1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,6,24,6,24,0,18,0,1,12,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,
0,11,19,2,3,0,2,0,0,3,0,0,1,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,
0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,
7,17,24,9,14,0,13,6,5,21,7,6,9,19,7,20,19,13,7,4,15,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
4,6,15,23,2,6,19,14,6,8,11,9,22,22,4,5,5,5,4,17,17,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0]);

y:=CambridgeMatrix(3,F,21,\[
0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
3,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,
0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,
8,21,9,10,1,3,4,0,22,3,3,0,2,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,
0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,
15,16,19,5,23,9,20,4,9,13,10,3,15,18,19,24,19,9,22,16,4,
18,1,13,21,21,3,6,2,7,4,9,11,8,4,20,4,1,15,18,17,22,
23,19,5,24,17,9,12,5,21,13,0,3,20,14,22,1,4,15,22,24,5,
21,7,8,12,10,17,16,1,18,20,24,6,5,11,10,9,10,16,2,5,12,
1,9,8,8,16,11,2,16,21,7,22,22,2,16,0,23,16,1,4,22,23]);

G<x,y>:=MatrixGroup<21,F|x,y>;
print "Group G is 3.L3(4):2a < GL(21,GF(25))";