"Source: Text/Geometry/Crv.text";
"Line: 5542";
"Date: Thu May 12 11:26:16 2022";
"Main: Thu May 25 10:02:38 2023";
// original file: Text/Geometry/Crv.text, line: 5542
// Example: H121E32 ()
print "Example: H121E32";
ei := GetEchoInput();
SetEchoInput(true);
P<x,y,z> := ProjectiveSpace(GF(7),2);
C := Curve(P,y^2*z - x^3 - x*z^2 - z^3);
F := FunctionField(C);
D := Divisor(C,F!(x/z));
Decomposition(D);
Decomposition(D div 2);
A, B := SignDecomposition(D);
IsEffective(A);
assert $1;
IsEffective(B);
assert $1;
A - B eq D;
assert $1;
SetEchoInput(ei);
