"Source: Text/Commut/RngDiff.text";
"Line: 567";
"Date: Thu Sep 25 14:47:46 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/Commut/RngDiff.text, line: 567
// Example: H121E8 ()
print "Example: H121E8";
ei := GetEchoInput();
SetEchoInput(true);
F<z>:=RationalDifferentialField(Rationals());
S<t>:=DifferentialLaurentSeriesRing(Rationals());
IsAlgebraicDifferentialField(F);
assert $1;
IsDifferentialSeriesRing(F);
assert not $1;
IsAlgebraicDifferentialField(S);
assert not $1;
IsDifferentialSeriesRing(S);
assert $1;
IsDifferentialLaurentSeriesRing(S);
assert $1;
SetEchoInput(ei);
