The LeftIdentity command returns a left identity element of a magma possessing one. If the magma has no left identity element, an exception is raised.

Note that a magma may possess more than one left identity element; only one is returned.

$\mathrm{with}\left(\mathrm{Magma}\right)\:$

$m≔⟨⟨⟨1\|2\|3⟩\,⟨2\|3\|1⟩\,⟨3\|1\|2⟩⟩⟩$

$m≔\left[\begin{array}{ccc}1& 2& 3\\ 2& 3& 1\\ 3& 1& 2\end{array}\right]$

$\mathrm{LeftIdentity}\left(m\right)$

$1$

The Magma[LeftIdentity] command was introduced in Maple 15.

For more information on Maple 15 changes, see Updates in Maple 15.