"Source: Text/Commut/RngDiff.text";
"Line: 1334";
"Date: Thu Sep 25 14:47:46 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/Commut/RngDiff.text, line: 1334
// Example: H121E25 ()
print "Example: H121E25";
ei := GetEchoInput();
SetEchoInput(true);
F<z> := RationalDifferentialField(Rationals());
R<D> := DifferentialOperatorRing(F);
L := z^2*D^2-1;
M<Y,DY> := DifferentialFieldExtension(L);
IsDifferentialField(M);
assert $1;
Derivative(Y);
Derivative(DY);
SetEchoInput(ei);
