An old question of T. Jech and K Prikry asks whether the existence of a precipitous ideal implies the existence of a normal precipitous one. The aim of the paper is to prove some results in the positive direction. In particular, it is shown that under some mild assumptions, the existence of a precipitous ideal over ℵ1 implies the existence of a normal precipitous ideal over ℵ1 once a Cohen subset is added to ℵ2.
展开▼
