This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Proof of it0e0 without ax-mulcom . Informally, a real number times 0 is 0, and E. r e. RR r = _i x. s by ax-cnre and renegid2 . (Contributed by SN, 30-Apr-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | sn-it0e0 | |- ( _i x. 0 ) = 0 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0cn | |- 0 e. CC |
|
| 2 | cnre | |- ( 0 e. CC -> E. a e. RR E. b e. RR 0 = ( a + ( _i x. b ) ) ) |
|
| 3 | oveq2 | |- ( 0 = ( a + ( _i x. b ) ) -> ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) |
|
| 4 | ax-icn | |- _i e. CC |
|
| 5 | 4 | a1i | |- ( b e. RR -> _i e. CC ) |
| 6 | recn | |- ( b e. RR -> b e. CC ) |
|
| 7 | 0cnd | |- ( b e. RR -> 0 e. CC ) |
|
| 8 | 5 6 7 | mulassd | |- ( b e. RR -> ( ( _i x. b ) x. 0 ) = ( _i x. ( b x. 0 ) ) ) |
| 9 | remul01 | |- ( b e. RR -> ( b x. 0 ) = 0 ) |
|
| 10 | 9 | oveq2d | |- ( b e. RR -> ( _i x. ( b x. 0 ) ) = ( _i x. 0 ) ) |
| 11 | 8 10 | eqtrd | |- ( b e. RR -> ( ( _i x. b ) x. 0 ) = ( _i x. 0 ) ) |
| 12 | 11 | ad2antlr | |- ( ( ( a e. RR /\ b e. RR ) /\ ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) -> ( ( _i x. b ) x. 0 ) = ( _i x. 0 ) ) |
| 13 | rernegcl | |- ( a e. RR -> ( 0 -R a ) e. RR ) |
|
| 14 | 13 | recnd | |- ( a e. RR -> ( 0 -R a ) e. CC ) |
| 15 | 14 | adantr | |- ( ( a e. RR /\ b e. RR ) -> ( 0 -R a ) e. CC ) |
| 16 | recn | |- ( a e. RR -> a e. CC ) |
|
| 17 | 16 | adantr | |- ( ( a e. RR /\ b e. RR ) -> a e. CC ) |
| 18 | 5 6 | mulcld | |- ( b e. RR -> ( _i x. b ) e. CC ) |
| 19 | 18 | adantl | |- ( ( a e. RR /\ b e. RR ) -> ( _i x. b ) e. CC ) |
| 20 | 15 17 19 | addassd | |- ( ( a e. RR /\ b e. RR ) -> ( ( ( 0 -R a ) + a ) + ( _i x. b ) ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) |
| 21 | renegid2 | |- ( a e. RR -> ( ( 0 -R a ) + a ) = 0 ) |
|
| 22 | 21 | oveq1d | |- ( a e. RR -> ( ( ( 0 -R a ) + a ) + ( _i x. b ) ) = ( 0 + ( _i x. b ) ) ) |
| 23 | sn-addlid | |- ( ( _i x. b ) e. CC -> ( 0 + ( _i x. b ) ) = ( _i x. b ) ) |
|
| 24 | 18 23 | syl | |- ( b e. RR -> ( 0 + ( _i x. b ) ) = ( _i x. b ) ) |
| 25 | 22 24 | sylan9eq | |- ( ( a e. RR /\ b e. RR ) -> ( ( ( 0 -R a ) + a ) + ( _i x. b ) ) = ( _i x. b ) ) |
| 26 | 20 25 | eqtr3d | |- ( ( a e. RR /\ b e. RR ) -> ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) = ( _i x. b ) ) |
| 27 | 26 | eqeq2d | |- ( ( a e. RR /\ b e. RR ) -> ( ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) <-> ( ( 0 -R a ) + 0 ) = ( _i x. b ) ) ) |
| 28 | 27 | biimpa | |- ( ( ( a e. RR /\ b e. RR ) /\ ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) -> ( ( 0 -R a ) + 0 ) = ( _i x. b ) ) |
| 29 | 28 | oveq1d | |- ( ( ( a e. RR /\ b e. RR ) /\ ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) -> ( ( ( 0 -R a ) + 0 ) x. 0 ) = ( ( _i x. b ) x. 0 ) ) |
| 30 | elre0re | |- ( a e. RR -> 0 e. RR ) |
|
| 31 | 13 30 | readdcld | |- ( a e. RR -> ( ( 0 -R a ) + 0 ) e. RR ) |
| 32 | 31 | ad2antrr | |- ( ( ( a e. RR /\ b e. RR ) /\ ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) -> ( ( 0 -R a ) + 0 ) e. RR ) |
| 33 | remul01 | |- ( ( ( 0 -R a ) + 0 ) e. RR -> ( ( ( 0 -R a ) + 0 ) x. 0 ) = 0 ) |
|
| 34 | 32 33 | syl | |- ( ( ( a e. RR /\ b e. RR ) /\ ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) -> ( ( ( 0 -R a ) + 0 ) x. 0 ) = 0 ) |
| 35 | 29 34 | eqtr3d | |- ( ( ( a e. RR /\ b e. RR ) /\ ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) -> ( ( _i x. b ) x. 0 ) = 0 ) |
| 36 | 12 35 | eqtr3d | |- ( ( ( a e. RR /\ b e. RR ) /\ ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) ) -> ( _i x. 0 ) = 0 ) |
| 37 | 36 | ex | |- ( ( a e. RR /\ b e. RR ) -> ( ( ( 0 -R a ) + 0 ) = ( ( 0 -R a ) + ( a + ( _i x. b ) ) ) -> ( _i x. 0 ) = 0 ) ) |
| 38 | 3 37 | syl5 | |- ( ( a e. RR /\ b e. RR ) -> ( 0 = ( a + ( _i x. b ) ) -> ( _i x. 0 ) = 0 ) ) |
| 39 | 38 | rexlimivv | |- ( E. a e. RR E. b e. RR 0 = ( a + ( _i x. b ) ) -> ( _i x. 0 ) = 0 ) |
| 40 | 1 2 39 | mp2b | |- ( _i x. 0 ) = 0 |