Proof of Theorem trcleq2
| Step | Hyp | Ref
| Expression |
| 1 | | predeq2 13882 |
. . . . . . . . . . 11
 Pred    Pred      |
| 2 | 1 | adantr 425 |
. . . . . . . . . 10
   Pred    Pred      |
| 3 | 2 | iuneq2dv 3279 |
. . . . . . . . 9
  Pred     Pred      |
| 4 | 3 | eqeq2d 1895 |
. . . . . . . 8
  
Pred 
   Pred       |
| 5 | 4 | opabbidv 3401 |
. . . . . . 7
      Pred         
Pred       |
| 6 | | rdgeq1 5142 |
. . . . . . 7
      Pred         
Pred            Pred      Pred           
Pred      Pred 
     |
| 7 | 5, 6 | syl 12 |
. . . . . 6
     
 
Pred 
    Pred            Pred      Pred       |
| 8 | | predeq2 13882 |
. . . . . . 7
 Pred    Pred      |
| 9 | | rdgeq2 5143 |
. . . . . . 7
Pred    Pred        
 
Pred 
    Pred            Pred      Pred       |
| 10 | 8, 9 | syl 12 |
. . . . . 6
     
 
Pred 
    Pred            Pred      Pred       |
| 11 | 7, 10 | eqtrd 1925 |
. . . . 5
     
 
Pred 
    Pred            Pred      Pred       |
| 12 | | reseq1 4218 |
. . . . 5
     
 
Pred 
    Pred            Pred      Pred            
Pred      Pred 
         
 
Pred 
    Pred        |
| 13 | 11, 12 | syl 12 |
. . . 4
         Pred      Pred    
         Pred      Pred        |
| 14 | 13 | rneqd 4188 |
. . 3
         Pred      Pred             
Pred      Pred 
      |
| 15 | 14 | unieqd 3188 |
. 2
 
        Pred      Pred            
 
Pred 
    Pred        |
| 16 | | df-trcl 13925 |
. 2
Trcl          
 
Pred 
    Pred       |
| 17 | | df-trcl 13925 |
. 2
Trcl          
 
Pred 
    Pred       |
| 18 | 15, 16, 17 | 3eqtr4g 1953 |
1
 Trcl    Trcl      |