2017-01-12 14:21:16 +0200 | asked a question | Coercion between quotients of $\mathbb{Z}$ Hello, It is said here that "in general there is no coercion between two different finite fields". When testing equality between elements of $\mathbb{Z}/(n)$ and $\mathbb{Z}/(m)$, why is there coercion to $\mathbb{Z}/(\gcd(m,n))$ only if $\gcd(m,n) \neq 1$ ? I understand that testing equality in the null ring is not "useful", but why is it so inhomogeneous ? If some automated procedure depends on that feature, it would surely need to consider |