"Source: Text/Geometry/ModAbVar.text";
"Line: 8213";
"Date: Thu Sep 25 14:47:45 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/Geometry/ModAbVar.text, line: 8213
// Example: H148E112 ()
print "Example: H148E112";
ei := GetEchoInput();
SetEchoInput(true);
A := JZero(23);
AtkinLehnerOperator(A,23);
HeckeOperator(A,2);
A := JZero(100); A;
w4 := AtkinLehnerOperator(A,4); 
Factorization(CharacteristicPolynomial(w4));
w25 := AtkinLehnerOperator(A,25); 
Factorization(CharacteristicPolynomial(w25));
w4*w25 eq AtkinLehnerOperator(A);
assert $1;
A := Js(17);
B := BaseExtend(A,CyclotomicField(17));
w := AtkinLehnerOperator(B);
Factorization(CharacteristicPolynomial(w));
A := Decomposition(JZero(65))[2]; A;
G := nTorsionSubgroup(A,2); G;
H := Subgroup([G.1]); H;
B := A/H; B;
T2 := HeckeOperator(B,2); T2;
FactoredCharacteristicPolynomial(T2);
SetEchoInput(ei);
