Metamath Proof Explorer

Theorem chpcl

Description: Closure for the second Chebyshev function. (Contributed by Mario Carneiro, 7-Apr-2016)

Ref Expression
Assertion chpcl 
|- ( A e. RR -> ( psi ` A ) e. RR )

Proof

Step Hyp Ref Expression
1 chpf 
 |-  psi : RR --> RR
2 1 ffvelrni 
 |-  ( A e. RR -> ( psi ` A ) e. RR )