A submagma of a magma is a subset that is closed under the specified binary operation.  Note that the empty set if vacuously a submagma of any magma.  Also, every magma is a submagma of itself.

The IsSubMagma( ss, m ) command returns true if the set ss is a submagma of the magma m, and returns false otherwise.

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

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