If R is commutative, show that these conditions
(a) The ideals of R are linearly ordered by inclusion, and
(b) All ideals I ⊆ R are idempotent
hold iff R is either (0) or a field.
Show that the following conditions on a ring R are equivalent:
(1) All ideals not equal R are prime.
(2) (a) The ideals of R are linearly ordered by inclusion, and (b) All ideals I ⊆ R are idempotent.