| Step | Hyp | Ref
| Expression |
| 1 | | rngcvalALTV.c |
. 2
RngCatALTV   |
| 2 | | df-rngcALTV 41960 |
. . . 4
RngCatALTV   
Rng  ![]_ ]_](_urbrack.gif)                  RngHomo      comp             RngHomo        RngHomo              |
| 3 | 2 | a1i 11 |
. . 3
 RngCatALTV    Rng  ![]_ ]_](_urbrack.gif)       
      
   RngHomo      comp             RngHomo        RngHomo               |
| 4 | | vex 3203 |
. . . . . 6
 |
| 5 | 4 | inex1 4799 |
. . . . 5
 Rng  |
| 6 | 5 | a1i 11 |
. . . 4
 
 
Rng   |
| 7 | | ineq1 3807 |
. . . . . 6
 
Rng 
Rng  |
| 8 | 7 | adantl 482 |
. . . . 5
 
 
Rng 
Rng  |
| 9 | | rngcvalALTV.b |
. . . . . 6
  Rng  |
| 10 | 9 | adantr 481 |
. . . . 5
 
  Rng  |
| 11 | 8, 10 | eqtr4d 2659 |
. . . 4
 
 
Rng   |
| 12 | | simpr 477 |
. . . . . 6
       |
| 13 | 12 | opeq2d 4409 |
. . . . 5
           
         |
| 14 | | eqidd 2623 |
. . . . . . . 8
      RngHomo   RngHomo    |
| 15 | 12, 12, 14 | mpt2eq123dv 6717 |
. . . . . . 7
        RngHomo      RngHomo     |
| 16 | | rngcvalALTV.h |
. . . . . . . 8
    RngHomo     |
| 17 | 16 | ad2antrr 762 |
. . . . . . 7
        RngHomo     |
| 18 | 15, 17 | eqtr4d 2659 |
. . . . . 6
        RngHomo     |
| 19 | 18 | opeq2d 4409 |
. . . . 5
             RngHomo   
        |
| 20 | 12 | sqxpeqd 5141 |
. . . . . . . 8
           |
| 21 | | eqidd 2623 |
. . . . . . . 8
           RngHomo        RngHomo               RngHomo        RngHomo           |
| 22 | 20, 12, 21 | mpt2eq123dv 6717 |
. . . . . . 7
               RngHomo        RngHomo                    RngHomo        RngHomo            |
| 23 | | rngcvalALTV.o |
. . . . . . . 8
           RngHomo        RngHomo            |
| 24 | 23 | ad2antrr 762 |
. . . . . . 7
               RngHomo        RngHomo            |
| 25 | 22, 24 | eqtr4d 2659 |
. . . . . 6
               RngHomo        RngHomo           |
| 26 | 25 | opeq2d 4409 |
. . . . 5
      comp             RngHomo        RngHomo            comp     |
| 27 | 13, 19, 26 | tpeq123d 4283 |
. . . 4
                      RngHomo      comp             RngHomo        RngHomo                  
      
   comp      |
| 28 | 6, 11, 27 | csbied2 3561 |
. . 3
 
  
Rng  ![]_ ]_](_urbrack.gif)       
      
   RngHomo      comp             RngHomo        RngHomo                  
      
   comp      |
| 29 | | rngcvalALTV.u |
. . . 4
   |
| 30 | | elex 3212 |
. . . 4
   |
| 31 | 29, 30 | syl 17 |
. . 3
   |
| 32 | | tpex 6957 |
. . . 4
                 comp   
 |
| 33 | 32 | a1i 11 |
. . 3
       
      
   comp      |
| 34 | 3, 28, 31, 33 | fvmptd 6288 |
. 2
 RngCatALTV        
      
   comp      |
| 35 | 1, 34 | syl5eq 2668 |
1
                  comp      |