Proof of Theorem iscat
| Step | Hyp | Ref
| Expression |
| 1 | | opeq1 2491 |
. . . . . . 7
         |
| 2 | 1 | opeq1d 2497 |
. . . . . 6
                
    |
| 3 | 2 | eleq1d 1543 |
. . . . 5
          
Ded
        
Ded  |
| 4 | | dmeq 3317 |
. . . . . . . . 9

  |
| 5 | | iscat.1 |
. . . . . . . . 9
 |
| 6 | 4, 5 | syl6eqr 1528 |
. . . . . . . 8

  |
| 7 | 6 | eleq2d 1544 |
. . . . . . 7
     |
| 8 | 6 | eleq2d 1544 |
. . . . . . . . 9
     |
| 9 | 6 | eleq2d 1544 |
. . . . . . . . . . 11
     |
| 10 | | fveq1 3729 |
. . . . . . . . . . . . . 14
           |
| 11 | 10 | eqeq1d 1486 |
. . . . . . . . . . . . 13
                     |
| 12 | | fveq1 3729 |
. . . . . . . . . . . . . 14
           |
| 13 | 12 | eqeq1d 1486 |
. . . . . . . . . . . . 13
                     |
| 14 | 11, 13 | anbi12d 630 |
. . . . . . . . . . . 12
                                         |
| 15 | 14 | imbi1d 615 |
. . . . . . . . . . 11
                                                                             |
| 16 | 9, 15 | imbi12d 628 |
. . . . . . . . . 10
                                                                                 |
| 17 | 16 | ralbidv2 1668 |
. . . . . . . . 9
                                                                                |
| 18 | 8, 17 | imbi12d 628 |
. . . . . . . 8
   
                                                                                |
| 19 | 18 | ralbidv2 1668 |
. . . . . . 7
    
                                     

                                       |
| 20 | 7, 19 | imbi12d 628 |
. . . . . 6
   
                                         

                                        |
| 21 | 20 | ralbidv2 1668 |
. . . . 5
    
 
                                      

                                       |
| 22 | 3, 21 | anbi12d 630 |
. . . 4
     
      Ded                                               
      Ded                                            |
| 23 | 6 | raleq1d 1792 |
. . . . . 6
                                    |
| 24 | 23 | ralbidv 1666 |
. . . . 5
    
                                   |
| 25 | | fveq1 3729 |
. . . . . . . . . 10
           |
| 26 | 25 | eqeq1d 1486 |
. . . . . . . . 9
             |
| 27 | 26 | imbi1d 615 |
. . . . . . . 8
                                 |
| 28 | 7, 27 | imbi12d 628 |
. . . . . . 7
                                     |
| 29 | 28 | ralbidv2 1668 |
. . . . . 6
                                    |
| 30 | 29 | ralbidv 1666 |
. . . . 5
    
                                   |
| 31 | 24, 30 | anbi12d 630 |
. . . 4
   
 
               
 
                                  
 
                  |
| 32 | 22, 31 | anbi12d 630 |
. . 3
             Ded  |