"Source: Text/LieTheory/RootSys.text";
"Line: 1179";
"Date: Tue Jun  7 22:27:15 2016";
"Main: Thu May 25 10:02:38 2023";
// original file: Text/LieTheory/RootSys.text, line: 1179
// Example: H103E13 ()
print "Example: H103E13";
ei := GetEchoInput();
SetEchoInput(true);
R := RootSystem("G2");
Sum(R, 1, Negative(R,5));
assert $1 eq 10;
IsPositive(R, 10);
assert not $1;
Negative(R, 10);
assert $1 eq 4;
P := PositiveRoots(R);
P[1] - P[5] eq -P[4];
assert $1;
SetEchoInput(ei);
