Metamath Proof Explorer


Theorem angvald

Description: The (signed) angle between two vectors is the argument of their quotient. Deduction form of angval . (Contributed by David Moews, 28-Feb-2017)

Ref Expression
Hypotheses ang.1
|- F = ( x e. ( CC \ { 0 } ) , y e. ( CC \ { 0 } ) |-> ( Im ` ( log ` ( y / x ) ) ) )
angvald.1
|- ( ph -> X e. CC )
angvald.2
|- ( ph -> X =/= 0 )
angvald.3
|- ( ph -> Y e. CC )
angvald.4
|- ( ph -> Y =/= 0 )
Assertion angvald
|- ( ph -> ( X F Y ) = ( Im ` ( log ` ( Y / X ) ) ) )

Proof

Step Hyp Ref Expression
1 ang.1
 |-  F = ( x e. ( CC \ { 0 } ) , y e. ( CC \ { 0 } ) |-> ( Im ` ( log ` ( y / x ) ) ) )
2 angvald.1
 |-  ( ph -> X e. CC )
3 angvald.2
 |-  ( ph -> X =/= 0 )
4 angvald.3
 |-  ( ph -> Y e. CC )
5 angvald.4
 |-  ( ph -> Y =/= 0 )
6 1 angval
 |-  ( ( ( X e. CC /\ X =/= 0 ) /\ ( Y e. CC /\ Y =/= 0 ) ) -> ( X F Y ) = ( Im ` ( log ` ( Y / X ) ) ) )
7 2 3 4 5 6 syl22anc
 |-  ( ph -> ( X F Y ) = ( Im ` ( log ` ( Y / X ) ) ) )