"Source: Text/Geometry/Scheme.text";
"Line: 7071";
"Date: Fri May 26 16:23:18 2023";
"Main: Thu May 25 10:02:38 2023";
// original file: Text/Geometry/Scheme.text, line: 7071
// Example: H119E55 ()
print "Example: H119E55";
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);
