"Source: Text/Commut/RngDiff.text";
"Line: 654";
"Date: Thu Sep 25 14:47:46 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/Commut/RngDiff.text, line: 654
// Example: H121E10 ()
print "Example: H121E10";
ei := GetEchoInput();
SetEchoInput(true);
S<t>:=DifferentialLaurentSeriesRing(Rationals());
Derivative(t);
IsDifferentialLaurentSeriesRing(S);
assert $1;
RelativePrecision(S);
assert $1 eq 20;
RelativePrecision(UnderlyingRing(S));
V<w>:=DifferentialLaurentSeriesRing(Rationals():Precision:=30);
RelativePrecision(V);
assert $1 eq 30;
RelativePrecision(V) eq RelativePrecision(UnderlyingRing(V));
assert $1;
SetEchoInput(ei);
