Metamath Proof Explorer


Theorem cnf

Description: A continuous function is a mapping. (Contributed by FL, 8-Dec-2006) (Revised by Mario Carneiro, 21-Aug-2015)

Ref Expression
Hypotheses iscnp2.1
|- X = U. J
iscnp2.2
|- Y = U. K
Assertion cnf
|- ( F e. ( J Cn K ) -> F : X --> Y )

Proof

Step Hyp Ref Expression
1 iscnp2.1
 |-  X = U. J
2 iscnp2.2
 |-  Y = U. K
3 1 2 iscn2
 |-  ( F e. ( J Cn K ) <-> ( ( J e. Top /\ K e. Top ) /\ ( F : X --> Y /\ A. x e. K ( `' F " x ) e. J ) ) )
4 3 simprbi
 |-  ( F e. ( J Cn K ) -> ( F : X --> Y /\ A. x e. K ( `' F " x ) e. J ) )
5 4 simpld
 |-  ( F e. ( J Cn K ) -> F : X --> Y )