Description: Index value of the df-unif slot. (Contributed by Thierry Arnoux, 17-Dec-2017) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | unifndx | |- ( UnifSet ` ndx ) = ; 1 3 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-unif | |- UnifSet = Slot ; 1 3 |
|
| 2 | 1nn0 | |- 1 e. NN0 |
|
| 3 | 3nn | |- 3 e. NN |
|
| 4 | 2 3 | decnncl | |- ; 1 3 e. NN |
| 5 | 1 4 | ndxarg | |- ( UnifSet ` ndx ) = ; 1 3 |