| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fveq2 |  |-  ( A = 0 -> ( abs ` A ) = ( abs ` 0 ) ) | 
						
							| 2 |  | abs0 |  |-  ( abs ` 0 ) = 0 | 
						
							| 3 | 1 2 | eqtrdi |  |-  ( A = 0 -> ( abs ` A ) = 0 ) | 
						
							| 4 |  | oveq2 |  |-  ( A = 0 -> ( x x. A ) = ( x x. 0 ) ) | 
						
							| 5 | 3 4 | eqeq12d |  |-  ( A = 0 -> ( ( abs ` A ) = ( x x. A ) <-> 0 = ( x x. 0 ) ) ) | 
						
							| 6 | 5 | anbi2d |  |-  ( A = 0 -> ( ( ( abs ` x ) = 1 /\ ( abs ` A ) = ( x x. A ) ) <-> ( ( abs ` x ) = 1 /\ 0 = ( x x. 0 ) ) ) ) | 
						
							| 7 | 6 | rexbidv |  |-  ( A = 0 -> ( E. x e. CC ( ( abs ` x ) = 1 /\ ( abs ` A ) = ( x x. A ) ) <-> E. x e. CC ( ( abs ` x ) = 1 /\ 0 = ( x x. 0 ) ) ) ) | 
						
							| 8 |  | simpl |  |-  ( ( A e. CC /\ A =/= 0 ) -> A e. CC ) | 
						
							| 9 | 8 | cjcld |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( * ` A ) e. CC ) | 
						
							| 10 |  | abscl |  |-  ( A e. CC -> ( abs ` A ) e. RR ) | 
						
							| 11 | 10 | adantr |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` A ) e. RR ) | 
						
							| 12 | 11 | recnd |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` A ) e. CC ) | 
						
							| 13 |  | abs00 |  |-  ( A e. CC -> ( ( abs ` A ) = 0 <-> A = 0 ) ) | 
						
							| 14 | 13 | necon3bid |  |-  ( A e. CC -> ( ( abs ` A ) =/= 0 <-> A =/= 0 ) ) | 
						
							| 15 | 14 | biimpar |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` A ) =/= 0 ) | 
						
							| 16 | 9 12 15 | divcld |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( ( * ` A ) / ( abs ` A ) ) e. CC ) | 
						
							| 17 |  | absdiv |  |-  ( ( ( * ` A ) e. CC /\ ( abs ` A ) e. CC /\ ( abs ` A ) =/= 0 ) -> ( abs ` ( ( * ` A ) / ( abs ` A ) ) ) = ( ( abs ` ( * ` A ) ) / ( abs ` ( abs ` A ) ) ) ) | 
						
							| 18 | 9 12 15 17 | syl3anc |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` ( ( * ` A ) / ( abs ` A ) ) ) = ( ( abs ` ( * ` A ) ) / ( abs ` ( abs ` A ) ) ) ) | 
						
							| 19 |  | abscj |  |-  ( A e. CC -> ( abs ` ( * ` A ) ) = ( abs ` A ) ) | 
						
							| 20 | 19 | adantr |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` ( * ` A ) ) = ( abs ` A ) ) | 
						
							| 21 |  | absidm |  |-  ( A e. CC -> ( abs ` ( abs ` A ) ) = ( abs ` A ) ) | 
						
							| 22 | 21 | adantr |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` ( abs ` A ) ) = ( abs ` A ) ) | 
						
							| 23 | 20 22 | oveq12d |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( ( abs ` ( * ` A ) ) / ( abs ` ( abs ` A ) ) ) = ( ( abs ` A ) / ( abs ` A ) ) ) | 
						
							| 24 | 12 15 | dividd |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( ( abs ` A ) / ( abs ` A ) ) = 1 ) | 
						
							| 25 | 18 23 24 | 3eqtrd |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` ( ( * ` A ) / ( abs ` A ) ) ) = 1 ) | 
						
							| 26 | 8 9 12 15 | divassd |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( ( A x. ( * ` A ) ) / ( abs ` A ) ) = ( A x. ( ( * ` A ) / ( abs ` A ) ) ) ) | 
						
							| 27 | 12 | sqvald |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( ( abs ` A ) ^ 2 ) = ( ( abs ` A ) x. ( abs ` A ) ) ) | 
						
							| 28 |  | absvalsq |  |-  ( A e. CC -> ( ( abs ` A ) ^ 2 ) = ( A x. ( * ` A ) ) ) | 
						
							| 29 | 28 | adantr |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( ( abs ` A ) ^ 2 ) = ( A x. ( * ` A ) ) ) | 
						
							| 30 | 27 29 | eqtr3d |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( ( abs ` A ) x. ( abs ` A ) ) = ( A x. ( * ` A ) ) ) | 
						
							| 31 | 12 12 15 30 | mvllmuld |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` A ) = ( ( A x. ( * ` A ) ) / ( abs ` A ) ) ) | 
						
							| 32 | 16 8 | mulcomd |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( ( ( * ` A ) / ( abs ` A ) ) x. A ) = ( A x. ( ( * ` A ) / ( abs ` A ) ) ) ) | 
						
							| 33 | 26 31 32 | 3eqtr4d |  |-  ( ( A e. CC /\ A =/= 0 ) -> ( abs ` A ) = ( ( ( * ` A ) / ( abs ` A ) ) x. A ) ) | 
						
							| 34 |  | fveqeq2 |  |-  ( x = ( ( * ` A ) / ( abs ` A ) ) -> ( ( abs ` x ) = 1 <-> ( abs ` ( ( * ` A ) / ( abs ` A ) ) ) = 1 ) ) | 
						
							| 35 |  | oveq1 |  |-  ( x = ( ( * ` A ) / ( abs ` A ) ) -> ( x x. A ) = ( ( ( * ` A ) / ( abs ` A ) ) x. A ) ) | 
						
							| 36 | 35 | eqeq2d |  |-  ( x = ( ( * ` A ) / ( abs ` A ) ) -> ( ( abs ` A ) = ( x x. A ) <-> ( abs ` A ) = ( ( ( * ` A ) / ( abs ` A ) ) x. A ) ) ) | 
						
							| 37 | 34 36 | anbi12d |  |-  ( x = ( ( * ` A ) / ( abs ` A ) ) -> ( ( ( abs ` x ) = 1 /\ ( abs ` A ) = ( x x. A ) ) <-> ( ( abs ` ( ( * ` A ) / ( abs ` A ) ) ) = 1 /\ ( abs ` A ) = ( ( ( * ` A ) / ( abs ` A ) ) x. A ) ) ) ) | 
						
							| 38 | 37 | rspcev |  |-  ( ( ( ( * ` A ) / ( abs ` A ) ) e. CC /\ ( ( abs ` ( ( * ` A ) / ( abs ` A ) ) ) = 1 /\ ( abs ` A ) = ( ( ( * ` A ) / ( abs ` A ) ) x. A ) ) ) -> E. x e. CC ( ( abs ` x ) = 1 /\ ( abs ` A ) = ( x x. A ) ) ) | 
						
							| 39 | 16 25 33 38 | syl12anc |  |-  ( ( A e. CC /\ A =/= 0 ) -> E. x e. CC ( ( abs ` x ) = 1 /\ ( abs ` A ) = ( x x. A ) ) ) | 
						
							| 40 |  | ax-icn |  |-  _i e. CC | 
						
							| 41 |  | absi |  |-  ( abs ` _i ) = 1 | 
						
							| 42 |  | it0e0 |  |-  ( _i x. 0 ) = 0 | 
						
							| 43 | 42 | eqcomi |  |-  0 = ( _i x. 0 ) | 
						
							| 44 | 41 43 | pm3.2i |  |-  ( ( abs ` _i ) = 1 /\ 0 = ( _i x. 0 ) ) | 
						
							| 45 |  | fveqeq2 |  |-  ( x = _i -> ( ( abs ` x ) = 1 <-> ( abs ` _i ) = 1 ) ) | 
						
							| 46 |  | oveq1 |  |-  ( x = _i -> ( x x. 0 ) = ( _i x. 0 ) ) | 
						
							| 47 | 46 | eqeq2d |  |-  ( x = _i -> ( 0 = ( x x. 0 ) <-> 0 = ( _i x. 0 ) ) ) | 
						
							| 48 | 45 47 | anbi12d |  |-  ( x = _i -> ( ( ( abs ` x ) = 1 /\ 0 = ( x x. 0 ) ) <-> ( ( abs ` _i ) = 1 /\ 0 = ( _i x. 0 ) ) ) ) | 
						
							| 49 | 48 | rspcev |  |-  ( ( _i e. CC /\ ( ( abs ` _i ) = 1 /\ 0 = ( _i x. 0 ) ) ) -> E. x e. CC ( ( abs ` x ) = 1 /\ 0 = ( x x. 0 ) ) ) | 
						
							| 50 | 40 44 49 | mp2an |  |-  E. x e. CC ( ( abs ` x ) = 1 /\ 0 = ( x x. 0 ) ) | 
						
							| 51 | 50 | a1i |  |-  ( A e. CC -> E. x e. CC ( ( abs ` x ) = 1 /\ 0 = ( x x. 0 ) ) ) | 
						
							| 52 | 7 39 51 | pm2.61ne |  |-  ( A e. CC -> E. x e. CC ( ( abs ` x ) = 1 /\ ( abs ` A ) = ( x x. A ) ) ) |