"Source: Text/Geometry/Scheme.text";
"Line: 7117";
"Date: Thu Sep 25 14:47:45 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/Geometry/Scheme.text, line: 7117
// Example: H122E55 ()
print "Example: H122E55";
ei := GetEchoInput();
SetEchoInput(true);
P<x,y,z,t> := ProjectiveSpace(RationalField(),3);
X := Scheme(P,[x*y+z*t,x^2-y^2+2*z^2-4*t^2]);
Dimension(X);
assert $1 eq 1;
time TangentVariety(X); 
time TangentVariety(X: PatchIndex := 4);
time IsInTangentVariety(X,P![1,2,3,4]);
assert not $1;
SetEchoInput(ei);
