Description: Utility theorem: index-independent form of df-cco . (Contributed by Mario Carneiro, 7-Jan-2017)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ccoid | |- comp = Slot ( comp ` ndx ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-cco | |- comp = Slot ; 1 5 |
|
| 2 | 1nn0 | |- 1 e. NN0 |
|
| 3 | 5nn | |- 5 e. NN |
|
| 4 | 2 3 | decnncl | |- ; 1 5 e. NN |
| 5 | 1 4 | ndxid | |- comp = Slot ( comp ` ndx ) |