Metamath Proof Explorer


Theorem crimi

Description: The imaginary part of a complex number representation. Definition 10-3.1 of Gleason p. 132. (Contributed by NM, 10-May-1999)

Ref Expression
Hypotheses crre.1
|- A e. RR
crre.2
|- B e. RR
Assertion crimi
|- ( Im ` ( A + ( _i x. B ) ) ) = B

Proof

Step Hyp Ref Expression
1 crre.1
 |-  A e. RR
2 crre.2
 |-  B e. RR
3 crim
 |-  ( ( A e. RR /\ B e. RR ) -> ( Im ` ( A + ( _i x. B ) ) ) = B )
4 1 2 3 mp2an
 |-  ( Im ` ( A + ( _i x. B ) ) ) = B