"Source: Text/Geometry/Scheme.text";
"Line: 5332";
"Date: Thu Sep 25 14:47:45 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/Geometry/Scheme.text, line: 5332
// Example: H122E37 ()
print "Example: H122E37";
ei := GetEchoInput();
SetEchoInput(true);
k := Rationals();
P<x,y,z,t> := ProjectiveSpace(k,3);
A := Scheme(P,Minors(M,2))
          where M is Matrix(CoordinateRing(P),2,3,[x,y,z,y,z,t]);
B := Scheme(P,x*t - y*z);
F<r,s,u,v> := RuledSurface(k,0,0);
HomAF := Maps(A,F);
HomBF := Maps(B,F);
HomAF;
i := map< A -> B | [y,x,t,z] >;
ii := map< HomBF -> HomAF | g :-> i * g >;
f := map< B -> F | [x,y,z,t] >;
Expand(ii(f)) eq Expand(i*f);
assert $1;
SetEchoInput(ei);
