"Source: Text/LieTheory/Cartan.text";
"Line: 391";
"Date: Fri Sep 26 12:10:11 2025";
"Main: Fri Sep 26 14:29:19 2025";
// original file: Text/LieTheory/Cartan.text, line: 391
// Example: H105E6 ()
print "Example: H105E6";
ei := GetEchoInput();
SetEchoInput(true);
C := Matrix(2,2, [ 2,-3, -1,2 ]);
C;
IsCartanMatrix(C);
assert $1;
CoxeterMatrix(C);

G := PathGraph(4);
AssignLabel(G, 1,2, 4);
AssignLabel(G, 3,4, 4);
CartanMatrix(G);
CartanMatrix(G : Symmetric, BaseField := "Cyclotomic");
SetEchoInput(ei);
