Ring commutative with a 1

218 Views Asked by At

I have seen in a book Commutative Algebra by Reid mention of a "ring commutative with a 1". Does that mean that addition and multiplication are commutative and that the multiplicative identity is 1 or it means that it is in some way commutative with respect to 1? Can anyone explain?

1

There are 1 best solutions below

7
On BEST ANSWER

In a ring, addition is always commutative, and therefore when we talk about commutative rings, what that means is that multiplication is commutative. If we add that the ring has a $1$, what that means is that the ring has an identity element with respect to multiplication (denoted by $1$).