Proof of Theorem efiatan2
| Step | Hyp | Ref
| Expression |
| 1 | | ax-icn 9995 |
. . . . 5
 |
| 2 | | atancl 24608 |
. . . . 5

arctan arctan    |
| 3 | | mulcl 10020 |
. . . . 5
  arctan   
arctan     |
| 4 | 1, 2, 3 | sylancr 695 |
. . . 4

arctan  arctan     |
| 5 | | efcl 14813 |
. . . 4
  arctan  
    arctan      |
| 6 | 4, 5 | syl 17 |
. . 3

arctan     arctan      |
| 7 | | ax-1cn 9994 |
. . . . 5
 |
| 8 | | atandm2 24604 |
. . . . . . 7

arctan             |
| 9 | 8 | simp1bi 1076 |
. . . . . 6

arctan   |
| 10 | 9 | sqcld 13006 |
. . . . 5

arctan       |
| 11 | | addcl 10018 |
. . . . 5
               |
| 12 | 7, 10, 11 | sylancr 695 |
. . . 4

arctan         |
| 13 | 12 | sqrtcld 14176 |
. . 3

arctan             |
| 14 | 12 | sqsqrtd 14178 |
. . . . 5

arctan                       |
| 15 | | atandm4 24606 |
. . . . . 6

arctan           |
| 16 | 15 | simprbi 480 |
. . . . 5

arctan         |
| 17 | 14, 16 | eqnetrd 2861 |
. . . 4

arctan                 |
| 18 | | sqne0 12930 |
. . . . 5
                         
             |
| 19 | 13, 18 | syl 17 |
. . . 4

arctan               
             |
| 20 | 17, 19 | mpbid 222 |
. . 3

arctan             |
| 21 | 6, 13, 20 | divcan4d 10807 |
. 2

arctan      
arctan                             
arctan      |
| 22 | | halfcn 11247 |
. . . . . . 7
   |
| 23 | 12, 16 | logcld 24317 |
. . . . . . 7

arctan             |
| 24 | | mulcl 10020 |
. . . . . . 7
                               |
| 25 | 22, 23, 24 | sylancr 695 |
. . . . . 6

arctan                 |
| 26 | | efadd 14824 |
. . . . . 6
   arctan                       arctan                       
arctan                         |
| 27 | 4, 25, 26 | syl2anc 693 |
. . . . 5

arctan      arctan                        arctan                         |
| 28 | | 2cn 11091 |
. . . . . . . . . . . 12
 |
| 29 | 28 | a1i 11 |
. . . . . . . . . . 11

arctan   |
| 30 | | mulcl 10020 |
. . . . . . . . . . . . . 14
 
     |
| 31 | 1, 9, 30 | sylancr 695 |
. . . . . . . . . . . . 13

arctan     |
| 32 | | addcl 10018 |
. . . . . . . . . . . . 13
  
        |
| 33 | 7, 31, 32 | sylancr 695 |
. . . . . . . . . . . 12

arctan       |
| 34 | 8 | simp3bi 1078 |
. . . . . . . . . . . 12

arctan       |
| 35 | 33, 34 | logcld 24317 |
. . . . . . . . . . 11

arctan           |
| 36 | 29, 35, 4 | subdid 10486 |
. . . . . . . . . 10

arctan           
arctan                  arctan       |
| 37 | | atanval 24611 |
. . . . . . . . . . . . 13

arctan arctan                          |
| 38 | 37 | oveq2d 6666 |
. . . . . . . . . . . 12

arctan    arctan     
 
      
                |
| 39 | 1 | a1i 11 |
. . . . . . . . . . . . 13

arctan   |
| 40 | 29, 39, 2 | mulassd 10063 |
. . . . . . . . . . . 12

arctan    arctan     arctan      |
| 41 | | halfcl 11257 |
. . . . . . . . . . . . . . . . . 18
 
   |
| 42 | 1, 41 | ax-mp 5 |
. . . . . . . . . . . . . . . . 17
   |
| 43 | 28, 1, 42 | mulassi 10049 |
. . . . . . . . . . . . . . . 16
       
     |
| 44 | 28, 1, 42 | mul12i 10231 |
. . . . . . . . . . . . . . . 16
  
          |
| 45 | | 2ne0 11113 |
. . . . . . . . . . . . . . . . . . 19
 |
| 46 | 1, 28, 45 | divcan2i 10768 |
. . . . . . . . . . . . . . . . . 18
     |
| 47 | 46 | oveq2i 6661 |
. . . . . . . . . . . . . . . . 17
         |
| 48 | | ixi 10656 |
. . . . . . . . . . . . . . . . 17
    |
| 49 | 47, 48 | eqtri 2644 |
. . . . . . . . . . . . . . . 16
        |
| 50 | 43, 44, 49 | 3eqtri 2648 |
. . . . . . . . . . . . . . 15
        |
| 51 | 50 | oveq1i 6660 |
. . . . . . . . . . . . . 14
   
                                            |
| 52 | | subcl 10280 |
. . . . . . . . . . . . . . . . . 18
  
        |
| 53 | 7, 31, 52 | sylancr 695 |
. . . . . . . . . . . . . . . . 17

arctan       |
| 54 | 8 | simp2bi 1077 |
. . . . . . . . . . . . . . . . 17

arctan       |
| 55 | 53, 54 | logcld 24317 |
. . . . . . . . . . . . . . . 16

arctan     
     |
| 56 | 55, 35 | subcld 10392 |
. . . . . . . . . . . . . . 15

arctan                     |
| 57 | 56 | mulm1d 10482 |
. . . . . . . . . . . . . 14

arctan                            
              |
| 58 | 51, 57 | syl5eq 2668 |
. . . . . . . . . . . . 13

arctan    
                            
              |
| 59 | | 2mulicn 11255 |
. . . . . . . . . . . . . . 15
   |
| 60 | 59 | a1i 11 |
. . . . . . . . . . . . . 14

arctan     |
| 61 | 42 | a1i 11 |
. . . . . . . . . . . . . 14

arctan     |
| 62 | 60, 61, 56 | mulassd 10063 |
. . . . . . . . . . . . 13

arctan    
                                                  |
| 63 | 55, 35 | negsubdi2d 10408 |
. . . . . . . . . . . . 13

arctan                                 
      |
| 64 | 58, 62, 63 | 3eqtr3d 2664 |
. . . . . . . . . . . 12

arctan                                               |
| 65 | 38, 40, 64 | 3eqtr3d 2664 |
. . . . . . . . . . 11

arctan   arctan                        |
| 66 | 65 | oveq2d 6666 |
. . . . . . . . . 10

arctan             
arctan                             
       |
| 67 | | mulcl 10020 |
. . . . . . . . . . . . 13
                       |
| 68 | 28, 35, 67 | sylancr 695 |
. . . . . . . . . . . 12

arctan             |
| 69 | 68, 35, 55 | subsubd 10420 |
. . . . . . . . . . 11

arctan                         
                              
      |
| 70 | 35 | 2timesd 11275 |
. . . . . . . . . . . . . 14

arctan                               |
| 71 | 70 | oveq1d 6665 |
. . . . . . . . . . . . 13

arctan                                                   |
| 72 | 35, 35 | pncand 10393 |
. . . . . . . . . . . . 13

arctan                                       |
| 73 | 71, 72 | eqtrd 2656 |
. . . . . . . . . . . 12

arctan                               |
| 74 | 73 | oveq1d 6665 |
. . . . . . . . . . 11

arctan                                                   |
| 75 | | atanlogadd 24641 |
. . . . . . . . . . . . 13

arctan                     |
| 76 | | logef 24328 |
. . . . . . . . . . . . 13
              
   
                   
                          |
| 77 | 75, 76 | syl 17 |
. . . . . . . . . . . 12

arctan                    
                          |
| 78 | | efadd 14824 |
. . . . . . . . . . . . . . 15
                                   
                                 |
| 79 | 35, 55, 78 | syl2anc 693 |
. . . . . . . . . . . . . 14

arctan                 
                                 |
| 80 | | eflog 24323 |
. . . . . . . . . . . . . . . 16
                             |
| 81 | 33, 34, 80 | syl2anc 693 |
. . . . . . . . . . . . . . 15

arctan                   |
| 82 | | eflog 24323 |
. . . . . . . . . . . . . . . 16
   
   
                     |
| 83 | 53, 54, 82 | syl2anc 693 |
. . . . . . . . . . . . . . 15

arctan                   |
| 84 | 81, 83 | oveq12d 6668 |
. . . . . . . . . . . . . 14

arctan                                       |
| 85 | | sq1 12958 |
. . . . . . . . . . . . . . . . 17
     |
| 86 | 85 | a1i 11 |
. . . . . . . . . . . . . . . 16

arctan       |
| 87 | | sqmul 12926 |
. . . . . . . . . . . . . . . . . 18
 
                   |
| 88 | 1, 9, 87 | sylancr 695 |
. . . . . . . . . . . . . . . . 17

arctan                   |
| 89 | | i2 12965 |
. . . . . . . . . . . . . . . . . . 19
      |
| 90 | 89 | oveq1i 6660 |
. . . . . . . . . . . . . . . . . 18
                  |
| 91 | 10 | mulm1d 10482 |
. . . . . . . . . . . . . . . . . 18

arctan               |
| 92 | 90, 91 | syl5eq 2668 |
. . . . . . . . . . . . . . . . 17

arctan                  |
| 93 | 88, 92 | eqtrd 2656 |
. . . . . . . . . . . . . . . 16

arctan              |
| 94 | 86, 93 | oveq12d 6668 |
. . . . . . . . . . . . . . 15

arctan                      |
| 95 | | subsq 12972 |
. . . . . . . . . . . . . . . 16
  
                          |
| 96 | 7, 31, 95 | sylancr 695 |
. . . . . . . . . . . . . . 15

arctan                         |
| 97 | | subneg 10330 |
. . . . . . . . . . . . . . . 16
                      |
| 98 | 7, 10, 97 | sylancr 695 |
. . . . . . . . . . . . . . 15

arctan                |
| 99 | 94, 96, 98 | 3eqtr3d 2664 |
. . . . . . . . . . . . . 14

arctan                   |
| 100 | 79, 84, 99 | 3eqtrd 2660 |
. . . . . . . . . . . . 13

arctan                 
             |
| 101 | 100 | fveq2d 6195 |
. . . . . . . . . . . 12

arctan                    
                  |
| 102 | 77, 101 | eqtr3d 2658 |
. . . . . . . . . . 11

arctan                               |
| 103 | 69, 74, 102 | 3eqtrd 2660 |
. . . . . . . . . 10

arctan                         
                 |
| 104 | 36, 66, 103 | 3eqtrd 2660 |
. . . . . . . . 9

arctan           
arctan                 |
| 105 | 104 | oveq1d 6665 |
. . . . . . . 8

arctan             arctan                    |
| 106 | 35, 4 | subcld 10392 |
. . . . . . . . 9

arctan           arctan      |
| 107 | 45 | a1i 11 |
. . . . . . . . 9

arctan   |
| 108 | 106, 29, 107 | divcan3d 10806 |
. . . . . . . 8

arctan             arctan                arctan      |
| 109 | 23, 29, 107 | divrec2d 10805 |
. . . . . . . 8

arctan                             |
| 110 | 105, 108,
109 | 3eqtr3d 2664 |
. . . . . . 7

arctan           arctan                    |
| 111 | 35, 4, 25 | subaddd 10410 |
. . . . . . 7

arctan            arctan                    arctan                             |
| 112 | 110, 111 | mpbid 222 |
. . . . . 6

arctan   arctan                            |
| 113 | 112 | fveq2d 6195 |
. . . . 5

arctan      arctan                                 |
| 114 | 27, 113 | eqtr3d 2658 |
. . . 4

arctan      arctan                                     |
| 115 | 22 | a1i 11 |
. . . . . . 7

arctan     |
| 116 | 12, 16, 115 | cxpefd 24458 |
. . . . . 6

arctan                                |
| 117 | | cxpsqrt 24449 |
. . . . . . 7
                              |
| 118 | 12, 117 | syl 17 |
. . . . . 6

arctan                        |
| 119 | 116, 118 | eqtr3d 2658 |
. . . . 5

arctan                               |
| 120 | 119 | oveq2d 6666 |
. . . 4

arctan      arctan                            arctan                 |
| 121 | 114, 120,
81 | 3eqtr3d 2664 |
. . 3

arctan      arctan                     |
| 122 | 121 | oveq1d 6665 |
. 2

arctan      
arctan                                            |
| 123 | 21, 122 | eqtr3d 2658 |
1

arctan     arctan                      |