if R is a ring, why is there an isomorphism between R/R and {0}?
I don't understand how is it even possible because R/R = R.
Thanks.
$\displaystyle [x],[y]\in R/R$
are equal iff
$\displaystyle x-y\in R$
This happen for all $\displaystyle x,y\in R$ so, $\displaystyle R/R$ has only one element:
$\displaystyle R/R=\{[0]\}$
Fernando Revilla