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 x A x B

Proof

Step Hyp Ref Expression
1 intimass A B y | x A y = x B
2 intima0 x A x B = y | x A y = x B
3 1 2 sseqtrri A B x A x B