Description: Projection of a factor of an indexed Cartesian product. (Contributed by Glauco Siliprandi, 24-Dec-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | fvixp2 | |- ( ( F e. X_ x e. A B /\ x e. A ) -> ( F ` x ) e. B ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elixp2 | |- ( F e. X_ x e. A B <-> ( F e. _V /\ F Fn A /\ A. x e. A ( F ` x ) e. B ) ) |
|
2 | 1 | simp3bi | |- ( F e. X_ x e. A B -> A. x e. A ( F ` x ) e. B ) |
3 | 2 | r19.21bi | |- ( ( F e. X_ x e. A B /\ x e. A ) -> ( F ` x ) e. B ) |