"Source: Text/LieTheory/GrpCox.text";
"Line: 1538";
"Date: Fri Sep 26 12:10:11 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/LieTheory/GrpCox.text, line: 1538
// Example: H108E19 ()
print "Example: H108E19";
ei := GetEchoInput();
SetEchoInput(true);
W := RootDatum("G2");
Sum(W, 1, Negative(W,5));
assert $1 eq 10;
IsPositive(W, 10);
assert not $1;
Negative(W, 10);
assert $1 eq 4;
P := PositiveRoots(W);
P[1] - P[5] eq -P[4];
assert $1;
SetEchoInput(ei);
