Description: Index value of the df-hom slot. (Contributed by Mario Carneiro, 7-Jan-2017) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | homndx | |- ( Hom ` ndx ) = ; 1 4 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-hom | |- Hom = Slot ; 1 4 |
|
| 2 | 1nn0 | |- 1 e. NN0 |
|
| 3 | 4nn | |- 4 e. NN |
|
| 4 | 2 3 | decnncl | |- ; 1 4 e. NN |
| 5 | 1 4 | ndxarg | |- ( Hom ` ndx ) = ; 1 4 |