At < http://mathoverflow.net/posts/219864/edit>, Er_Ro asked the following question. > Let $R $ be a commutative ring with identity and $R[x] $ its polynomial ring. I am looking for a ring with finitely many idempotent and an unextended ideal $I $ in $R [x] $ such that $R[x]/I$ has infinitely many idempotent? It is important and whenever $R $ is a local ring, I want to know that there is any example in this case.