TRACE _ _ _ _ _ _ _ _ _ _ _ _ operator
The trace operator finds the trace of its matrix argument.
trace(<expression>) or trace <simple\_expression>
<expression> or <simple\_expression> must evaluate to a square matrix.
matrix a; a := mat((x1,y1),(x2,y2))$ trace a; X1 + Y2
The trace is the sum of the entries along the diagonal of a square matrix. Given a non-matrix expression, or a non-square matrix, trace returns an error message.