Description: Index value of the df-ocomp slot. (Contributed by Mario Carneiro, 25-Oct-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | ocndx | ⊢ ( oc ‘ ndx ) = ; 1 1 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-ocomp | ⊢ oc = Slot ; 1 1 | |
2 | 1nn0 | ⊢ 1 ∈ ℕ0 | |
3 | 1nn | ⊢ 1 ∈ ℕ | |
4 | 2 3 | decnncl | ⊢ ; 1 1 ∈ ℕ |
5 | 1 4 | ndxarg | ⊢ ( oc ‘ ndx ) = ; 1 1 |