Metamath Proof Explorer


Theorem recld

Description: The real part of a complex number is real (closure law). (Contributed by Mario Carneiro, 29-May-2016)

Ref Expression
Hypothesis recld.1
|- ( ph -> A e. CC )
Assertion recld
|- ( ph -> ( Re ` A ) e. RR )

Proof

Step Hyp Ref Expression
1 recld.1
 |-  ( ph -> A e. CC )
2 recl
 |-  ( A e. CC -> ( Re ` A ) e. RR )
3 1 2 syl
 |-  ( ph -> ( Re ` A ) e. RR )