This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: The natural logarithm of _i . (Contributed by Scott Fenton, 13-Apr-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | logi | |- ( log ` _i ) = ( _i x. ( _pi / 2 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | efhalfpi | |- ( exp ` ( _i x. ( _pi / 2 ) ) ) = _i |
|
| 2 | ax-icn | |- _i e. CC |
|
| 3 | ine0 | |- _i =/= 0 |
|
| 4 | halfpire | |- ( _pi / 2 ) e. RR |
|
| 5 | 4 | recni | |- ( _pi / 2 ) e. CC |
| 6 | 2 5 | mulcli | |- ( _i x. ( _pi / 2 ) ) e. CC |
| 7 | pipos | |- 0 < _pi |
|
| 8 | pire | |- _pi e. RR |
|
| 9 | lt0neg2 | |- ( _pi e. RR -> ( 0 < _pi <-> -u _pi < 0 ) ) |
|
| 10 | 8 9 | ax-mp | |- ( 0 < _pi <-> -u _pi < 0 ) |
| 11 | 7 10 | mpbi | |- -u _pi < 0 |
| 12 | halfpos2 | |- ( _pi e. RR -> ( 0 < _pi <-> 0 < ( _pi / 2 ) ) ) |
|
| 13 | 8 12 | ax-mp | |- ( 0 < _pi <-> 0 < ( _pi / 2 ) ) |
| 14 | 7 13 | mpbi | |- 0 < ( _pi / 2 ) |
| 15 | 8 | renegcli | |- -u _pi e. RR |
| 16 | 0re | |- 0 e. RR |
|
| 17 | 15 16 4 | lttri | |- ( ( -u _pi < 0 /\ 0 < ( _pi / 2 ) ) -> -u _pi < ( _pi / 2 ) ) |
| 18 | 11 14 17 | mp2an | |- -u _pi < ( _pi / 2 ) |
| 19 | reim | |- ( ( _pi / 2 ) e. CC -> ( Re ` ( _pi / 2 ) ) = ( Im ` ( _i x. ( _pi / 2 ) ) ) ) |
|
| 20 | 5 19 | ax-mp | |- ( Re ` ( _pi / 2 ) ) = ( Im ` ( _i x. ( _pi / 2 ) ) ) |
| 21 | rere | |- ( ( _pi / 2 ) e. RR -> ( Re ` ( _pi / 2 ) ) = ( _pi / 2 ) ) |
|
| 22 | 4 21 | ax-mp | |- ( Re ` ( _pi / 2 ) ) = ( _pi / 2 ) |
| 23 | 20 22 | eqtr3i | |- ( Im ` ( _i x. ( _pi / 2 ) ) ) = ( _pi / 2 ) |
| 24 | 18 23 | breqtrri | |- -u _pi < ( Im ` ( _i x. ( _pi / 2 ) ) ) |
| 25 | 8 | a1i | |- ( T. -> _pi e. RR ) |
| 26 | 25 25 | ltaddposd | |- ( T. -> ( 0 < _pi <-> _pi < ( _pi + _pi ) ) ) |
| 27 | 7 26 | mpbii | |- ( T. -> _pi < ( _pi + _pi ) ) |
| 28 | picn | |- _pi e. CC |
|
| 29 | 28 | times2i | |- ( _pi x. 2 ) = ( _pi + _pi ) |
| 30 | 27 29 | breqtrrdi | |- ( T. -> _pi < ( _pi x. 2 ) ) |
| 31 | 2rp | |- 2 e. RR+ |
|
| 32 | 31 | a1i | |- ( T. -> 2 e. RR+ ) |
| 33 | 25 25 32 | ltdivmul2d | |- ( T. -> ( ( _pi / 2 ) < _pi <-> _pi < ( _pi x. 2 ) ) ) |
| 34 | 30 33 | mpbird | |- ( T. -> ( _pi / 2 ) < _pi ) |
| 35 | 34 | mptru | |- ( _pi / 2 ) < _pi |
| 36 | 4 8 35 | ltleii | |- ( _pi / 2 ) <_ _pi |
| 37 | 23 36 | eqbrtri | |- ( Im ` ( _i x. ( _pi / 2 ) ) ) <_ _pi |
| 38 | ellogrn | |- ( ( _i x. ( _pi / 2 ) ) e. ran log <-> ( ( _i x. ( _pi / 2 ) ) e. CC /\ -u _pi < ( Im ` ( _i x. ( _pi / 2 ) ) ) /\ ( Im ` ( _i x. ( _pi / 2 ) ) ) <_ _pi ) ) |
|
| 39 | 6 24 37 38 | mpbir3an | |- ( _i x. ( _pi / 2 ) ) e. ran log |
| 40 | logeftb | |- ( ( _i e. CC /\ _i =/= 0 /\ ( _i x. ( _pi / 2 ) ) e. ran log ) -> ( ( log ` _i ) = ( _i x. ( _pi / 2 ) ) <-> ( exp ` ( _i x. ( _pi / 2 ) ) ) = _i ) ) |
|
| 41 | 2 3 39 40 | mp3an | |- ( ( log ` _i ) = ( _i x. ( _pi / 2 ) ) <-> ( exp ` ( _i x. ( _pi / 2 ) ) ) = _i ) |
| 42 | 1 41 | mpbir | |- ( log ` _i ) = ( _i x. ( _pi / 2 ) ) |