olemus
ring, mille korrutustehe on kommutatiivne
=
a ring in which the multiplication operation is commutative

ülevaateid
https://en.wikipedia.org/wiki/Commutative_ring

https://resources.saylor.org/wwwresources/archived/site/wp-content/uploads/2011/04/Commutative-Ring.pdf

https://www2.math.upenn.edu/~chai/602-3f20/shatz-gallier/alg3.pdf