"Source: Text/Geometry/AlgSrf.text";
"Line: 6329";
"Date: Mon Mar 29 22:30:18 2021";
"Main: Thu May 25 10:02:38 2023";
// original file: Text/Geometry/AlgSrf.text, line: 6329
// Example: H123E38 ()
print "Example: H123E38";
ei := GetEchoInput();
SetEchoInput(true);
r4<x,y,z,w> := PolynomialRing(RationalField(),4);
surf := x^3 + 2*y^3 + 3*z^3 + 5*w^3 - 2*x*y*(z-w) + (x+y+z+w)^3;
cont := ContravariantsOfCubicSurface(surf);
cov := ClassicalCovariantsOfCubicSurface(surf);
ApplyContravariant(cont[1],cov[1]) / (2^11 * 3^9);
ClebschSalmonInvariants(surf)[1];
SetEchoInput(ei);
