Abstract :
We show that: (1) if R is a Noetherian domain, then R {Xλ}λ Λ 1 is a strong Mori domain; (2) if R is a strong Mori domain, then R {Xλ}λ Λ 1 is a Mori domain; but (3) there exists a strong Mori domain R such that R X is not a strong Mori domain.
