Proof of Theorem cmtfval
| Step | Hyp | Ref
| Expression |
| 1 | | elisset 2299 |
. 2

  |
| 2 | | fveq2 4681 |
. . . . . . . 8
 base  base    |
| 3 | | cmtfval.b |
. . . . . . . 8
base   |
| 4 | 2, 3 | syl6eqr 1946 |
. . . . . . 7
 base    |
| 5 | 4 | eleq2d 1964 |
. . . . . 6
  base     |
| 6 | 4 | eleq2d 1964 |
. . . . . 6
  base     |
| 7 | | fveq2 4681 |
. . . . . . . . 9
 join  join    |
| 8 | | cmtfval.j |
. . . . . . . . 9
join   |
| 9 | 7, 8 | syl6eqr 1946 |
. . . . . . . 8
 join    |
| 10 | | fveq2 4681 |
. . . . . . . . . 10
 meet  meet    |
| 11 | | cmtfval.m |
. . . . . . . . . 10
meet   |
| 12 | 10, 11 | syl6eqr 1946 |
. . . . . . . . 9
 meet    |
| 13 | 12 | opreqd 4899 |
. . . . . . . 8
   meet          |
| 14 | | eqidd 1885 |
. . . . . . . . 9
   |
| 15 | | fveq2 4681 |
. . . . . . . . . . 11
 oc  oc    |
| 16 | | cmtfval.o |
. . . . . . . . . . 11
oc   |
| 17 | 15, 16 | syl6eqr 1946 |
. . . . . . . . . 10
 oc    |
| 18 | 17 | fveq1d 4683 |
. . . . . . . . 9
  oc           |
| 19 | 12, 14, 18 | opreq123d 10153 |
. . . . . . . 8
   meet    oc                |
| 20 | 9, 13, 19 | opreq123d 10153 |
. . . . . . 7
    meet     join     meet    oc                         |
| 21 | 20 | eqeq2d 1895 |
. . . . . 6
     meet     join     meet    oc                          |
| 22 | 5, 6, 21 | 3anbi123d 1168 |
. . . . 5
   base  base     meet     join     meet    oc                             |
| 23 | 22 | opabbidv 3401 |
. . . 4
      base 
base     meet     join     meet    oc           
                      |
| 24 | | df-cmt 16906 |
. . . 4
cm       base 
base     meet     join     meet    oc           |
| 25 | | df-3an 860 |
. . . . . 6
                                         |
| 26 | 25 | opabbii 3402 |
. . . . 5
  
                         

                   |
| 27 | | fvex 4689 |
. . . . . . . 8
base   |
| 28 | 3, 27 | eqeltri 1967 |
. . . . . . 7
 |
| 29 | 28, 28 | xpex 4096 |
. . . . . 6

  |
| 30 | | opabssxp 4060 |
. . . . . 6
  
                         |
| 31 | 29, 30 | ssexi 3456 |
. . . . 5
  
                       |
| 32 | 26, 31 | eqeltri 1967 |
. . . 4
  
                     |
| 33 | 23, 24, 32 | fvmpt 5015 |
. . 3

cm      
                    |
| 34 | | cmtfval.c |
. . 3
cm   |
| 35 | 33, 34 | syl5eq 1940 |
. 2

  
                      |
| 36 | 1, 35 | syl 12 |
1

  
                      |