"Source: Text/Group/GrpMatInf.text";
"Line: 972";
"Date: Thu Apr  1 11:57:57 2021";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/Group/GrpMatInf.text, line: 972
// Example: H68E6 ()
print "Example: H68E6";
ei := GetEchoInput();
SetEchoInput(true);
 R<x> := PolynomialRing(Integers());
 K<y> := NumberField(x^4-420*x^2+40000);
 G := GL (2, K);
 a := G![y,1,0,-1];
 b:= G![y/(y + 1), 1, 0, 1/y];
 H := sub <GL(2, K) | a, b>;
time IsFinite(H);
assert not $1;
SetEchoInput(ei);
