A ring $R$ is called reduced if it has no nilpotent elements (non-trivial). Assume that $R \neq 0$ and consider the following four conditions on $R$:
the ring $R$ is reduced
the localization $R_{P}$ at any its prime ideal $P \subset R$ is reduced
the ring $R$ is an integral domain
the localization $R_{P}$ at any its prime ideal $P \subset R$ is an integral domain.
Question: for every pair of distinct integers $a , b \in \{1,2,3,4\}$, determine if condition $(a)$ implies $(b)$.
So far, I have been able to show that:
(i) 1 doesn't imply 3 (I gave counter example) and 3 implies 1
(ii) I showed 1 if and only if 2.
(iii) I showed 3 implies 4 but 4 doesn't imply 3.
Our ring R is commutative and contains 1.
Please guys I will be highly happy and grateful if the pairs $(1,4), (4,1), (2,3), (3,2), (2,4, (4,2).$ Counter examples will be great too. Thanks.