This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Value of the complex power function. (Contributed by Mario Carneiro, 2-Aug-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | cxpval | |- ( ( A e. CC /\ B e. CC ) -> ( A ^c B ) = if ( A = 0 , if ( B = 0 , 1 , 0 ) , ( exp ` ( B x. ( log ` A ) ) ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simpl | |- ( ( x = A /\ y = B ) -> x = A ) |
|
| 2 | 1 | eqeq1d | |- ( ( x = A /\ y = B ) -> ( x = 0 <-> A = 0 ) ) |
| 3 | simpr | |- ( ( x = A /\ y = B ) -> y = B ) |
|
| 4 | 3 | eqeq1d | |- ( ( x = A /\ y = B ) -> ( y = 0 <-> B = 0 ) ) |
| 5 | 4 | ifbid | |- ( ( x = A /\ y = B ) -> if ( y = 0 , 1 , 0 ) = if ( B = 0 , 1 , 0 ) ) |
| 6 | 1 | fveq2d | |- ( ( x = A /\ y = B ) -> ( log ` x ) = ( log ` A ) ) |
| 7 | 3 6 | oveq12d | |- ( ( x = A /\ y = B ) -> ( y x. ( log ` x ) ) = ( B x. ( log ` A ) ) ) |
| 8 | 7 | fveq2d | |- ( ( x = A /\ y = B ) -> ( exp ` ( y x. ( log ` x ) ) ) = ( exp ` ( B x. ( log ` A ) ) ) ) |
| 9 | 2 5 8 | ifbieq12d | |- ( ( x = A /\ y = B ) -> if ( x = 0 , if ( y = 0 , 1 , 0 ) , ( exp ` ( y x. ( log ` x ) ) ) ) = if ( A = 0 , if ( B = 0 , 1 , 0 ) , ( exp ` ( B x. ( log ` A ) ) ) ) ) |
| 10 | df-cxp | |- ^c = ( x e. CC , y e. CC |-> if ( x = 0 , if ( y = 0 , 1 , 0 ) , ( exp ` ( y x. ( log ` x ) ) ) ) ) |
|
| 11 | ax-1cn | |- 1 e. CC |
|
| 12 | 0cn | |- 0 e. CC |
|
| 13 | 11 12 | ifcli | |- if ( B = 0 , 1 , 0 ) e. CC |
| 14 | 13 | elexi | |- if ( B = 0 , 1 , 0 ) e. _V |
| 15 | fvex | |- ( exp ` ( B x. ( log ` A ) ) ) e. _V |
|
| 16 | 14 15 | ifex | |- if ( A = 0 , if ( B = 0 , 1 , 0 ) , ( exp ` ( B x. ( log ` A ) ) ) ) e. _V |
| 17 | 9 10 16 | ovmpoa | |- ( ( A e. CC /\ B e. CC ) -> ( A ^c B ) = if ( A = 0 , if ( B = 0 , 1 , 0 ) , ( exp ` ( B x. ( log ` A ) ) ) ) ) |