The HasLeftIdentity command determines whether a magma m has a left identity element.  It returns true if m has a left identity element, and returns false' otherwise.

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

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

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

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

$\mathrm{true}$

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

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