| Step | Hyp | Ref
| Expression |
| 1 | | funcrngcsetcALT.f |
. . . . . . 7
         |
| 2 | | fveq2 6191 |
. . . . . . . 8
           |
| 3 | 2 | cbvmptv 4750 |
. . . . . . 7
             |
| 4 | 1, 3 | syl6eq 2672 |
. . . . . 6
         |
| 5 | | coires1 5653 |
. . . . . . 7
                  |
| 6 | | funcrngcsetcALT.r |
. . . . . . . . . . . 12
RngCat   |
| 7 | | funcrngcsetcALT.b |
. . . . . . . . . . . 12
     |
| 8 | | funcrngcsetcALT.u |
. . . . . . . . . . . 12
 WUni |
| 9 | 6, 7, 8 | rngcbas 41965 |
. . . . . . . . . . 11
  Rng  |
| 10 | 9 | eleq2d 2687 |
. . . . . . . . . 10
   Rng   |
| 11 | | elin 3796 |
. . . . . . . . . . 11
  Rng 
Rng  |
| 12 | 11 | simplbi 476 |
. . . . . . . . . 10
  Rng   |
| 13 | 10, 12 | syl6bi 243 |
. . . . . . . . 9
     |
| 14 | 13 | ssrdv 3609 |
. . . . . . . 8

  |
| 15 | 14 | resmptd 5452 |
. . . . . . 7
                 |
| 16 | 5, 15 | syl5req 2669 |
. . . . . 6
                  |
| 17 | 4, 16 | eqtrd 2656 |
. . . . 5
            |
| 18 | | funcrngcsetcALT.g |
. . . . . . 7
    RngHomo      |
| 19 | | coires1 5653 |
. . . . . . . . 9

            RngHomo                
RngHomo    |
| 20 | | eqid 2622 |
. . . . . . . . . . . . 13
         |
| 21 | | eqid 2622 |
. . . . . . . . . . . . 13
         |
| 22 | 20, 21 | rnghmf 41899 |
. . . . . . . . . . . 12
  RngHomo 
              |
| 23 | | fvex 6201 |
. . . . . . . . . . . . . 14
     |
| 24 | | fvex 6201 |
. . . . . . . . . . . . . 14
     |
| 25 | 23, 24 | pm3.2i 471 |
. . . . . . . . . . . . 13
           |
| 26 | | elmapg 7870 |
. . . . . . . . . . . . 13
                     
               |
| 27 | 25, 26 | mp1i 13 |
. . . . . . . . . . . 12
 

     
    
               |
| 28 | 22, 27 | syl5ibr 236 |
. . . . . . . . . . 11
 

  RngHomo      
        |
| 29 | 28 | ssrdv 3609 |
. . . . . . . . . 10
 

 RngHomo 
            |
| 30 | 29 | resabs1d 5428 |
. . . . . . . . 9
 

           
 RngHomo  
 RngHomo     |
| 31 | 19, 30 | syl5req 2669 |
. . . . . . . 8
 

 RngHomo   
            RngHomo      |
| 32 | 31 | mpt2eq3dva 6719 |
. . . . . . 7
  
 RngHomo           
       RngHomo       |
| 33 | 18, 32 | eqtrd 2656 |
. . . . . 6
   
            RngHomo       |
| 34 | 7 | a1i 11 |
. . . . . . 7
       |
| 35 | 7 | a1i 11 |
. . . . . . 7
 
       |
| 36 | | fvresi 6439 |
. . . . . . . . . . . 12
        |
| 37 | 36 | adantr 481 |
. . . . . . . . . . 11
 
        |
| 38 | 37 | adantl 482 |
. . . . . . . . . 10
 

         |
| 39 | | fvresi 6439 |
. . . . . . . . . . . 12
        |
| 40 | 39 | adantl 482 |
. . . . . . . . . . 11
 
        |
| 41 | 40 | adantl 482 |
. . . . . . . . . 10
 

         |
| 42 | 38, 41 | oveq12d 6668 |
. . . . . . . . 9
 

                                 
                |
| 43 | | eqidd 2623 |
. . . . . . . . . 10
 

   
                            |
| 44 | | simprr 796 |
. . . . . . . . . . . . 13
   
 

    |
| 45 | 44 | fveq2d 6195 |
. . . . . . . . . . . 12
   
 

            |
| 46 | | simprl 794 |
. . . . . . . . . . . . 13
   
 

    |
| 47 | 46 | fveq2d 6195 |
. . . . . . . . . . . 12
   
 

            |
| 48 | 45, 47 | oveq12d 6668 |
. . . . . . . . . . 11
   
 

                        |
| 49 | 48 | reseq2d 5396 |
. . . . . . . . . 10
   
 

                          |
| 50 | 13 | com12 32 |
. . . . . . . . . . . 12
     |
| 51 | 50 | adantr 481 |
. . . . . . . . . . 11
 
     |
| 52 | 51 | impcom 446 |
. . . . . . . . . 10
 

 
  |
| 53 | 9 | eleq2d 2687 |
. . . . . . . . . . . . 13
   Rng   |
| 54 | | elin 3796 |
. . . . . . . . . . . . . 14
  Rng 
Rng  |
| 55 | 54 | simplbi 476 |
. . . . . . . . . . . . 13
  Rng   |
| 56 | 53, 55 | syl6bi 243 |
. . . . . . . . . . . 12
     |
| 57 | 56 | a1d 25 |
. . . . . . . . . . 11
       |
| 58 | 57 | imp32 449 |
. . . . . . . . . 10
 

    |
| 59 | | ovex 6678 |
. . . . . . . . . . . 12
           |
| 60 | 59 | a1i 11 |
. . . . . . . . . . 11
 

      
       |
| 61 | 60 | resiexd 6480 |
. . . . . . . . . 10
 

               |
| 62 | 43, 49, 52, 58, 61 | ovmpt2d 6788 |
. . . . . . . . 9
 

          
                      |
| 63 | 42, 62 | eqtr2d 2657 |
. . . . . . . 8
 

                                           |
| 64 | | eqidd 2623 |
. . . . . . . . . 10
 

   
 RngHomo       RngHomo      |
| 65 | | oveq12 6659 |
. . . . . . . . . . . 12
 
  RngHomo   RngHomo    |
| 66 | 65 | reseq2d 5396 |
. . . . . . . . . . 11
 
  RngHomo    RngHomo     |
| 67 | 66 | adantl 482 |
. . . . . . . . . 10
   
 

   RngHomo    RngHomo     |
| 68 | | simprl 794 |
. . . . . . . . . 10
 

 
  |
| 69 | | simprr 796 |
. . . . . . . . . 10
 

    |
| 70 | | ovex 6678 |
. . . . . . . . . . . 12
 RngHomo   |
| 71 | 70 | a1i 11 |
. . . . . . . . . . 11
 

   RngHomo
   |
| 72 | 71 | resiexd 6480 |
. . . . . . . . . 10
 

   RngHomo     |
| 73 | 64, 67, 68, 69, 72 | ovmpt2d 6788 |
. . . . . . . . 9
 

       RngHomo       RngHomo     |
| 74 | 73 | eqcomd 2628 |
. . . . . . . 8
 

   RngHomo        RngHomo        |
| 75 | 63, 74 | coeq12d 5286 |
. . . . . . 7
 

               RngHomo             
                      
 RngHomo         |
| 76 | 34, 35, 75 | mpt2eq123dva 6716 |
. . . . . 6
  
             RngHomo                        
                      
 RngHomo          |
| 77 | 33, 76 | eqtrd 2656 |
. . . . 5
                    
                      
 RngHomo          |
| 78 | 17, 77 | opeq12d 4410 |
. . . 4
                                  
                      
 RngHomo           |
| 79 | | eqid 2622 |
. . . . 5
         |
| 80 | | eqid 2622 |
. . . . . 6
ExtStrCat  ExtStrCat   |
| 81 | | eqidd 2623 |
. . . . . 6
     |
| 82 | | eqidd 2623 |
. . . . . 6
  
 RngHomo       RngHomo      |
| 83 | 6, 80, 7, 8, 81, 82 | rngcifuestrc 41997 |
. . . . 5
    ExtStrCat     
 RngHomo      |
| 84 | | funcrngcsetcALT.s |
. . . . . 6
     |
| 85 | | eqid 2622 |
. . . . . 6
   ExtStrCat      ExtStrCat    |
| 86 | | eqid 2622 |
. . . . . 6
         |
| 87 | 80, 8 | estrcbas 16765 |
. . . . . . 7
    ExtStrCat     |
| 88 | 87 | mpteq1d 4738 |
. . . . . 6
           ExtStrCat          |
| 89 | | fveq2 6191 |
. . . . . . . . . . 11
           |
| 90 | 89 | oveq2d 6666 |
. . . . . . . . . 10
               
       |
| 91 | 90 | reseq2d 5396 |
. . . . . . . . 9
                
        |
| 92 | | fveq2 6191 |
. . . . . . . . . . 11
           |
| 93 | 92 | oveq1d 6665 |
. . . . . . . . . 10
               
       |
| 94 | 93 | reseq2d 5396 |
. . . . . . . . 9
                
        |
| 95 | 91, 94 | cbvmpt2v 6735 |
. . . . . . . 8
      
             
        |
| 96 | 95 | a1i 11 |
. . . . . . 7
  
                            |
| 97 | | eqidd 2623 |
. . . . . . . 8
                         |
| 98 | 87, 87, 97 | mpt2eq123dv 6717 |
. . . . . . 7
  
                ExtStrCat       ExtStrCat                 |
| 99 | 96, 98 | eqtrd 2656 |
. . . . . 6
  
                ExtStrCat       ExtStrCat                 |
| 100 | 80, 84, 85, 86, 8, 88, 99 | funcestrcsetc 16789 |
. . . . 5
         ExtStrCat                    |
| 101 | 79, 83, 100 | cofuval2 16547 |
. . . 4
           
             func       RngHomo     
                              
                      
 RngHomo           |
| 102 | 78, 101 | eqtr4d 2659 |
. . 3
              
             func       RngHomo        |
| 103 | | df-br 4654 |
. . . . 5

   ExtStrCat     
 RngHomo   
    
 RngHomo      ExtStrCat     |
| 104 | 83, 103 | sylib 208 |
. . . 4
 
     RngHomo      ExtStrCat     |
| 105 | | df-br 4654 |
. . . . 5
         ExtStrCat 
   
                     
              ExtStrCat 
   |
| 106 | 100, 105 | sylib 208 |
. . . 4
          
              ExtStrCat 
   |
| 107 | 104, 106 | cofucl 16548 |
. . 3
           
             func       RngHomo     
    |
| 108 | 102, 107 | eqeltrd 2701 |
. 2
        |
| 109 | | df-br 4654 |
. 2
    
       |
| 110 | 108, 109 | sylibr 224 |
1
       |