Metamath Proof Explorer


Theorem intimass2

Description: The image under the intersection of relations is a subset of the intersection of the images. (Contributed by RP, 13-Apr-2020)

Ref Expression
Assertion intimass2
|- ( |^| A " B ) C_ |^|_ x e. A ( x " B )

Proof

Step Hyp Ref Expression
1 intimass
 |-  ( |^| A " B ) C_ |^| { y | E. x e. A y = ( x " B ) }
2 intima0
 |-  |^|_ x e. A ( x " B ) = |^| { y | E. x e. A y = ( x " B ) }
3 1 2 sseqtrri
 |-  ( |^| A " B ) C_ |^|_ x e. A ( x " B )