Proof of Theorem fnetr
| Step | Hyp | Ref
| Expression |
| 1 | | eqid 1884 |
. . . 4
   |
| 2 | | eqid 1884 |
. . . 4
   |
| 3 | 1, 2 | isfne2 15481 |
. . 3

 Fne             |
| 4 | 3 | 3ad2ant1 897 |
. 2
  Fne Fne  Fne
            |
| 5 | | fnerel 15479 |
. . . . . 6
Fne |
| 6 | 5 | brrelexi 4029 |
. . . . 5
 Fne
  |
| 7 | 6 | 3ad2ant3 899 |
. . . 4
  Fne Fne   |
| 8 | | simp2 877 |
. . . 4
  Fne Fne Fne  |
| 9 | | eqid 1884 |
. . . . 5
   |
| 10 | 1, 9 | fnebas 15483 |
. . . 4
  Fne 
   |
| 11 | 7, 8, 10 | syl11anc 524 |
. . 3
  Fne Fne     |
| 12 | 9, 2 | fnebas 15483 |
. . . 4
  Fne     |
| 13 | 12 | 3adant2 895 |
. . 3
  Fne Fne     |
| 14 | 11, 13 | eqtrd 1925 |
. 2
  Fne Fne     |
| 15 | 7 | adantr 425 |
. . . . . 6
   Fne Fne      |
| 16 | 8 | adantr 425 |
. . . . . 6
   Fne Fne    Fne  |
| 17 | | simprl 450 |
. . . . . 6
   Fne Fne      |
| 18 | | simprr 451 |
. . . . . 6
   Fne Fne      |
| 19 | | fnessex 15484 |
. . . . . 6
   Fne

 

   |
| 20 | 15, 16, 17, 18, 19 | syl31anc 1103 |
. . . . 5
   Fne Fne    

   |
| 21 | | simpll1 915 |
. . . . . . . . 9
    Fne
Fne

         |
| 22 | | simpll3 917 |
. . . . . . . . 9
    Fne
Fne

       Fne  |
| 23 | | simprl 450 |
. . . . . . . . 9
    Fne
Fne

         |
| 24 | | simprrl 458 |
. . . . . . . . 9
    Fne
Fne

         |
| 25 | | fnessex 15484 |
. . . . . . . . 9
   Fne

 

   |
| 26 | 21, 22, 23, 24, 25 | syl31anc 1103 |
. . . . . . . 8
    Fne
Fne

            |
| 27 | | sstr2 2623 |
. . . . . . . . . . . . 13
 
   |
| 28 | 27 | com12 14 |
. . . . . . . . . . . 12
     |
| 29 | 28 | adantl 424 |
. . . . . . . . . . 11
  

   |
| 30 | 29 | ad2antll 443 |
. . . . . . . . . 10
    Fne
Fne

       
   |
| 31 | 30 | anim2d 620 |
. . . . . . . . 9
    Fne
Fne

               |
| 32 | 31 | reximdv 2202 |
. . . . . . . 8
    Fne
Fne

                 |
| 33 | 26, 32 | mpd 29 |
. . . . . . 7
    Fne
Fne

            |
| 34 | 33 | exp32 408 |
. . . . . 6
   Fne Fne    
   

     |
| 35 | 34 | r19.23adv 2215 |
. . . . 5
   Fne Fne       

     |
| 36 | 20, 35 | mpd 29 |
. . . 4
   Fne Fne    

   |
| 37 | 36 | ex 402 |
. . 3
  Fne Fne          |
| 38 | 37 | r19.21aivv 2183 |
. 2
  Fne Fne 



   |
| 39 | 4, 14, 38 | mpbir2and 802 |
1
  Fne Fne Fne  |