Metamath Proof Explorer


Theorem cnref1o

Description: There is a natural one-to-one mapping from ( RR X. RR ) to CC , where we map <. x , y >. to ( x + (i x. y ) ) . In our construction of the complex numbers, this is in fact our definition_ of CC (see df-c ), but in the axiomatic treatment we can only show that there is the expected mapping between these two sets. (Contributed by Mario Carneiro, 16-Jun-2013) (Revised by Mario Carneiro, 17-Feb-2014)

Ref Expression
Hypothesis cnref1o.1
|- F = ( x e. RR , y e. RR |-> ( x + ( _i x. y ) ) )
Assertion cnref1o
|- F : ( RR X. RR ) -1-1-onto-> CC

Proof

Step Hyp Ref Expression
1 cnref1o.1
 |-  F = ( x e. RR , y e. RR |-> ( x + ( _i x. y ) ) )
2 ovex
 |-  ( x + ( _i x. y ) ) e. _V
3 1 2 fnmpoi
 |-  F Fn ( RR X. RR )
4 1st2nd2
 |-  ( z e. ( RR X. RR ) -> z = <. ( 1st ` z ) , ( 2nd ` z ) >. )
5 4 fveq2d
 |-  ( z e. ( RR X. RR ) -> ( F ` z ) = ( F ` <. ( 1st ` z ) , ( 2nd ` z ) >. ) )
6 df-ov
 |-  ( ( 1st ` z ) F ( 2nd ` z ) ) = ( F ` <. ( 1st ` z ) , ( 2nd ` z ) >. )
7 5 6 eqtr4di
 |-  ( z e. ( RR X. RR ) -> ( F ` z ) = ( ( 1st ` z ) F ( 2nd ` z ) ) )
8 xp1st
 |-  ( z e. ( RR X. RR ) -> ( 1st ` z ) e. RR )
9 xp2nd
 |-  ( z e. ( RR X. RR ) -> ( 2nd ` z ) e. RR )
10 oveq1
 |-  ( x = ( 1st ` z ) -> ( x + ( _i x. y ) ) = ( ( 1st ` z ) + ( _i x. y ) ) )
11 oveq2
 |-  ( y = ( 2nd ` z ) -> ( _i x. y ) = ( _i x. ( 2nd ` z ) ) )
12 11 oveq2d
 |-  ( y = ( 2nd ` z ) -> ( ( 1st ` z ) + ( _i x. y ) ) = ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) )
13 ovex
 |-  ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) e. _V
14 10 12 1 13 ovmpo
 |-  ( ( ( 1st ` z ) e. RR /\ ( 2nd ` z ) e. RR ) -> ( ( 1st ` z ) F ( 2nd ` z ) ) = ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) )
15 8 9 14 syl2anc
 |-  ( z e. ( RR X. RR ) -> ( ( 1st ` z ) F ( 2nd ` z ) ) = ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) )
16 7 15 eqtrd
 |-  ( z e. ( RR X. RR ) -> ( F ` z ) = ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) )
17 8 recnd
 |-  ( z e. ( RR X. RR ) -> ( 1st ` z ) e. CC )
18 ax-icn
 |-  _i e. CC
19 9 recnd
 |-  ( z e. ( RR X. RR ) -> ( 2nd ` z ) e. CC )
20 mulcl
 |-  ( ( _i e. CC /\ ( 2nd ` z ) e. CC ) -> ( _i x. ( 2nd ` z ) ) e. CC )
21 18 19 20 sylancr
 |-  ( z e. ( RR X. RR ) -> ( _i x. ( 2nd ` z ) ) e. CC )
22 17 21 addcld
 |-  ( z e. ( RR X. RR ) -> ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) e. CC )
23 16 22 eqeltrd
 |-  ( z e. ( RR X. RR ) -> ( F ` z ) e. CC )
24 23 rgen
 |-  A. z e. ( RR X. RR ) ( F ` z ) e. CC
25 ffnfv
 |-  ( F : ( RR X. RR ) --> CC <-> ( F Fn ( RR X. RR ) /\ A. z e. ( RR X. RR ) ( F ` z ) e. CC ) )
26 3 24 25 mpbir2an
 |-  F : ( RR X. RR ) --> CC
27 8 9 jca
 |-  ( z e. ( RR X. RR ) -> ( ( 1st ` z ) e. RR /\ ( 2nd ` z ) e. RR ) )
28 xp1st
 |-  ( w e. ( RR X. RR ) -> ( 1st ` w ) e. RR )
29 xp2nd
 |-  ( w e. ( RR X. RR ) -> ( 2nd ` w ) e. RR )
30 28 29 jca
 |-  ( w e. ( RR X. RR ) -> ( ( 1st ` w ) e. RR /\ ( 2nd ` w ) e. RR ) )
31 cru
 |-  ( ( ( ( 1st ` z ) e. RR /\ ( 2nd ` z ) e. RR ) /\ ( ( 1st ` w ) e. RR /\ ( 2nd ` w ) e. RR ) ) -> ( ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) = ( ( 1st ` w ) + ( _i x. ( 2nd ` w ) ) ) <-> ( ( 1st ` z ) = ( 1st ` w ) /\ ( 2nd ` z ) = ( 2nd ` w ) ) ) )
32 27 30 31 syl2an
 |-  ( ( z e. ( RR X. RR ) /\ w e. ( RR X. RR ) ) -> ( ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) = ( ( 1st ` w ) + ( _i x. ( 2nd ` w ) ) ) <-> ( ( 1st ` z ) = ( 1st ` w ) /\ ( 2nd ` z ) = ( 2nd ` w ) ) ) )
33 fveq2
 |-  ( z = w -> ( F ` z ) = ( F ` w ) )
34 fveq2
 |-  ( z = w -> ( 1st ` z ) = ( 1st ` w ) )
35 fveq2
 |-  ( z = w -> ( 2nd ` z ) = ( 2nd ` w ) )
36 35 oveq2d
 |-  ( z = w -> ( _i x. ( 2nd ` z ) ) = ( _i x. ( 2nd ` w ) ) )
37 34 36 oveq12d
 |-  ( z = w -> ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) = ( ( 1st ` w ) + ( _i x. ( 2nd ` w ) ) ) )
38 33 37 eqeq12d
 |-  ( z = w -> ( ( F ` z ) = ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) <-> ( F ` w ) = ( ( 1st ` w ) + ( _i x. ( 2nd ` w ) ) ) ) )
39 38 16 vtoclga
 |-  ( w e. ( RR X. RR ) -> ( F ` w ) = ( ( 1st ` w ) + ( _i x. ( 2nd ` w ) ) ) )
40 16 39 eqeqan12d
 |-  ( ( z e. ( RR X. RR ) /\ w e. ( RR X. RR ) ) -> ( ( F ` z ) = ( F ` w ) <-> ( ( 1st ` z ) + ( _i x. ( 2nd ` z ) ) ) = ( ( 1st ` w ) + ( _i x. ( 2nd ` w ) ) ) ) )
41 1st2nd2
 |-  ( w e. ( RR X. RR ) -> w = <. ( 1st ` w ) , ( 2nd ` w ) >. )
42 4 41 eqeqan12d
 |-  ( ( z e. ( RR X. RR ) /\ w e. ( RR X. RR ) ) -> ( z = w <-> <. ( 1st ` z ) , ( 2nd ` z ) >. = <. ( 1st ` w ) , ( 2nd ` w ) >. ) )
43 fvex
 |-  ( 1st ` z ) e. _V
44 fvex
 |-  ( 2nd ` z ) e. _V
45 43 44 opth
 |-  ( <. ( 1st ` z ) , ( 2nd ` z ) >. = <. ( 1st ` w ) , ( 2nd ` w ) >. <-> ( ( 1st ` z ) = ( 1st ` w ) /\ ( 2nd ` z ) = ( 2nd ` w ) ) )
46 42 45 bitrdi
 |-  ( ( z e. ( RR X. RR ) /\ w e. ( RR X. RR ) ) -> ( z = w <-> ( ( 1st ` z ) = ( 1st ` w ) /\ ( 2nd ` z ) = ( 2nd ` w ) ) ) )
47 32 40 46 3bitr4d
 |-  ( ( z e. ( RR X. RR ) /\ w e. ( RR X. RR ) ) -> ( ( F ` z ) = ( F ` w ) <-> z = w ) )
48 47 biimpd
 |-  ( ( z e. ( RR X. RR ) /\ w e. ( RR X. RR ) ) -> ( ( F ` z ) = ( F ` w ) -> z = w ) )
49 48 rgen2
 |-  A. z e. ( RR X. RR ) A. w e. ( RR X. RR ) ( ( F ` z ) = ( F ` w ) -> z = w )
50 dff13
 |-  ( F : ( RR X. RR ) -1-1-> CC <-> ( F : ( RR X. RR ) --> CC /\ A. z e. ( RR X. RR ) A. w e. ( RR X. RR ) ( ( F ` z ) = ( F ` w ) -> z = w ) ) )
51 26 49 50 mpbir2an
 |-  F : ( RR X. RR ) -1-1-> CC
52 cnre
 |-  ( w e. CC -> E. u e. RR E. v e. RR w = ( u + ( _i x. v ) ) )
53 oveq1
 |-  ( x = u -> ( x + ( _i x. y ) ) = ( u + ( _i x. y ) ) )
54 oveq2
 |-  ( y = v -> ( _i x. y ) = ( _i x. v ) )
55 54 oveq2d
 |-  ( y = v -> ( u + ( _i x. y ) ) = ( u + ( _i x. v ) ) )
56 ovex
 |-  ( u + ( _i x. v ) ) e. _V
57 53 55 1 56 ovmpo
 |-  ( ( u e. RR /\ v e. RR ) -> ( u F v ) = ( u + ( _i x. v ) ) )
58 57 eqeq2d
 |-  ( ( u e. RR /\ v e. RR ) -> ( w = ( u F v ) <-> w = ( u + ( _i x. v ) ) ) )
59 58 2rexbiia
 |-  ( E. u e. RR E. v e. RR w = ( u F v ) <-> E. u e. RR E. v e. RR w = ( u + ( _i x. v ) ) )
60 52 59 sylibr
 |-  ( w e. CC -> E. u e. RR E. v e. RR w = ( u F v ) )
61 fveq2
 |-  ( z = <. u , v >. -> ( F ` z ) = ( F ` <. u , v >. ) )
62 df-ov
 |-  ( u F v ) = ( F ` <. u , v >. )
63 61 62 eqtr4di
 |-  ( z = <. u , v >. -> ( F ` z ) = ( u F v ) )
64 63 eqeq2d
 |-  ( z = <. u , v >. -> ( w = ( F ` z ) <-> w = ( u F v ) ) )
65 64 rexxp
 |-  ( E. z e. ( RR X. RR ) w = ( F ` z ) <-> E. u e. RR E. v e. RR w = ( u F v ) )
66 60 65 sylibr
 |-  ( w e. CC -> E. z e. ( RR X. RR ) w = ( F ` z ) )
67 66 rgen
 |-  A. w e. CC E. z e. ( RR X. RR ) w = ( F ` z )
68 dffo3
 |-  ( F : ( RR X. RR ) -onto-> CC <-> ( F : ( RR X. RR ) --> CC /\ A. w e. CC E. z e. ( RR X. RR ) w = ( F ` z ) ) )
69 26 67 68 mpbir2an
 |-  F : ( RR X. RR ) -onto-> CC
70 df-f1o
 |-  ( F : ( RR X. RR ) -1-1-onto-> CC <-> ( F : ( RR X. RR ) -1-1-> CC /\ F : ( RR X. RR ) -onto-> CC ) )
71 51 69 70 mpbir2an
 |-  F : ( RR X. RR ) -1-1-onto-> CC