Metamath Proof Explorer


Theorem cnpcl

Description: The value of a continuous function from J to K at point P belongs to the underlying set of topology K . (Contributed by FL, 27-Dec-2006) (Revised by Mario Carneiro, 21-Aug-2015)

Ref Expression
Hypotheses iscnp2.1
|- X = U. J
iscnp2.2
|- Y = U. K
Assertion cnpcl
|- ( ( F e. ( ( J CnP K ) ` P ) /\ A e. X ) -> ( F ` A ) e. Y )

Proof

Step Hyp Ref Expression
1 iscnp2.1
 |-  X = U. J
2 iscnp2.2
 |-  Y = U. K
3 1 2 cnpf
 |-  ( F e. ( ( J CnP K ) ` P ) -> F : X --> Y )
4 3 ffvelrnda
 |-  ( ( F e. ( ( J CnP K ) ` P ) /\ A e. X ) -> ( F ` A ) e. Y )