Algebra over a commutative ring
An algebra
( π₯ + π¦ ) π§ = π₯ π§ + π¦ π§ π§ ( π₯ + π¦ ) = π§ π₯ + π§ π¦ ( πΌ π₯ ) ( π½ π¦ ) = ( πΌ π½ ) ( π₯ π¦ )
Thus it is a Magma object in Category of modules over a commutative ring.