Metamath Proof Explorer


Theorem cjmulrcli

Description: A complex number times its conjugate is real. (Contributed by NM, 11-May-1999)

Ref Expression
Hypothesis recl.1
|- A e. CC
Assertion cjmulrcli
|- ( A x. ( * ` A ) ) e. RR

Proof

Step Hyp Ref Expression
1 recl.1
 |-  A e. CC
2 cjmulrcl
 |-  ( A e. CC -> ( A x. ( * ` A ) ) e. RR )
3 1 2 ax-mp
 |-  ( A x. ( * ` A ) ) e. RR