"Source: Text/Commut/RngDiff.text";
"Line: 3003";
"Date: Thu Sep 25 14:47:46 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/Commut/RngDiff.text, line: 3003
// Example: H121E53 ()
print "Example: H121E53";
ei := GetEchoInput();
SetEchoInput(true);
F<z> := RationalDifferentialField(Rationals());
R<D> := DifferentialOperatorRing(F);
LCLM(D, D-z);
L1 := D^3+z*D^2+D-z;
L2 := D^2+(z-3)*D-3*z+1;
LeastCommonLeftMultiple(L1, L2);
L, U, V := ExtendedLeastCommonLeftMultiple(L1, L2);
L, U, V;
L eq U*L1;
assert $1;
L eq V*L2;
assert $1;
L, Q := ExtendedLeastCommonLeftMultiple([D,D+1,z*D+1]);
L;
Q[3]*(z*D+1) eq L;
assert $1;
SetEchoInput(ei);
