2.VerbOf a prime ideal
q
{\displaystyle q}
of a ring
R
′
{\displaystyle R'}
with subring
R
{\displaystyle R}
, to intersect with
R
{\displaystyle R}
at some other prime ideal
p
{\displaystyle p}
;
q
{\displaystyle q}
lies over
p
{\displaystyle p}
if and only if
q
∩
R
=
p
{\displaystyle q\cap R=p}
.