| Step | Hyp | Ref
| Expression |
| 1 | | elex 3212 |
. 2
   |
| 2 | | ipoval.i |
. . 3
toInc   |
| 3 | | vex 3203 |
. . . . . . . 8
 |
| 4 | 3, 3 | xpex 6962 |
. . . . . . 7
   |
| 5 | | simpl 473 |
. . . . . . . . . 10
    
   
  |
| 6 | | vex 3203 |
. . . . . . . . . . 11
 |
| 7 | | vex 3203 |
. . . . . . . . . . 11
 |
| 8 | 6, 7 | prss 4351 |
. . . . . . . . . 10
 
      |
| 9 | 5, 8 | sylibr 224 |
. . . . . . . . 9
    
     |
| 10 | 9 | ssopab2i 5003 |
. . . . . . . 8
       
      
   |
| 11 | | df-xp 5120 |
. . . . . . . 8
     

   |
| 12 | 10, 11 | sseqtr4i 3638 |
. . . . . . 7
       
     |
| 13 | 4, 12 | ssexi 4803 |
. . . . . 6
       
   |
| 14 | 13 | a1i 11 |
. . . . 5
        
    |
| 15 | | sseq2 3627 |
. . . . . . . 8
    
      |
| 16 | 15 | anbi1d 741 |
. . . . . . 7
     
    
    |
| 17 | 16 | opabbidv 4716 |
. . . . . 6
        
         
    |
| 18 | | ipoval.l |
. . . . . 6
           |
| 19 | 17, 18 | syl6eqr 2674 |
. . . . 5
        
 
 |
| 20 | | simpl 473 |
. . . . . . . 8
 
  |
| 21 | 20 | opeq2d 4409 |
. . . . . . 7
 
     
      
   |
| 22 | | simpr 477 |
. . . . . . . . 9
 
 |
| 23 | 22 | fveq2d 6195 |
. . . . . . . 8
 
ordTop  ordTop
  |
| 24 | 23 | opeq2d 4409 |
. . . . . . 7
 
 TopSet   ordTop    TopSet  
ordTop    |
| 25 | 21, 24 | preq12d 4276 |
. . . . . 6
 
      
   TopSet   ordTop              TopSet   ordTop     |
| 26 | 22 | opeq2d 4409 |
. . . . . . 7
 
     
      
  |
| 27 | | id 22 |
. . . . . . . . . 10
   |
| 28 | | rabeq 3192 |
. . . . . . . . . . 11
           |
| 29 | 28 | unieqd 4446 |
. . . . . . . . . 10
             |
| 30 | 27, 29 | mpteq12dv 4733 |
. . . . . . . . 9
                 |
| 31 | 30 | adantr 481 |
. . . . . . . 8
 
                |
| 32 | 31 | opeq2d 4409 |
. . . . . . 7
 
     

      
                |
| 33 | 26, 32 | preq12d 4276 |
. . . . . 6
 
                                                 |
| 34 | 25, 33 | uneq12d 3768 |
. . . . 5
 
           TopSet   ordTop          
       

                
   TopSet   ordTop
 
                          |
| 35 | 14, 19, 34 | csbied2 3561 |
. . . 4
             ![]_ ]_](_urbrack.gif)            TopSet   ordTop          
       

                
   TopSet   ordTop
 
                          |
| 36 | | df-ipo 17152 |
. . . 4
toInc      
       ![]_ ]_](_urbrack.gif)            TopSet   ordTop          
       

           |
| 37 | | prex 4909 |
. . . . 5
          TopSet   ordTop    |
| 38 | | prex 4909 |
. . . . 5
                        |
| 39 | 37, 38 | unex 6956 |
. . . 4
       
   TopSet   ordTop
 
                         |
| 40 | 35, 36, 39 | fvmpt 6282 |
. . 3
 toInc         
   TopSet   ordTop
 
                          |
| 41 | 2, 40 | syl5eq 2668 |
. 2
            TopSet   ordTop         
                   |
| 42 | 1, 41 | syl 17 |
1
            TopSet   ordTop         
                   |