Metamath Proof Explorer


Theorem intpreima

Description: Preimage of an intersection. (Contributed by FL, 28-Apr-2012)

Ref Expression
Assertion intpreima Fun F A F -1 A = x A F -1 x

Proof

Step Hyp Ref Expression
1 intiin A = x A x
2 1 imaeq2i F -1 A = F -1 x A x
3 iinpreima Fun F A F -1 x A x = x A F -1 x
4 2 3 eqtrid Fun F A F -1 A = x A F -1 x