Metamath Proof Explorer


Theorem cjf

Description: Domain and codomain of the conjugate function. (Contributed by Mario Carneiro, 6-Nov-2013)

Ref Expression
Assertion cjf
|- * : CC --> CC

Proof

Step Hyp Ref Expression
1 df-cj
 |-  * = ( x e. CC |-> ( iota_ y e. CC ( ( x + y ) e. RR /\ ( _i x. ( x - y ) ) e. RR ) ) )
2 cju
 |-  ( x e. CC -> E! y e. CC ( ( x + y ) e. RR /\ ( _i x. ( x - y ) ) e. RR ) )
3 riotacl
 |-  ( E! y e. CC ( ( x + y ) e. RR /\ ( _i x. ( x - y ) ) e. RR ) -> ( iota_ y e. CC ( ( x + y ) e. RR /\ ( _i x. ( x - y ) ) e. RR ) ) e. CC )
4 2 3 syl
 |-  ( x e. CC -> ( iota_ y e. CC ( ( x + y ) e. RR /\ ( _i x. ( x - y ) ) e. RR ) ) e. CC )
5 1 4 fmpti
 |-  * : CC --> CC