"Source: Text/LieTheory/Cartan.text";
"Line: 108";
"Date: Fri Sep 26 12:10:11 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/LieTheory/Cartan.text, line: 108
// Example: H105E1 ()
print "Example: H105E1";
ei := GetEchoInput();
SetEchoInput(true);
M := SymmetricMatrix([1, 3,1, 2,3,1]);
M;
IsCoxeterMatrix(M);
assert $1;
SetEchoInput(ei);
