Theorem ocndx

Description: Index value of the df-ocomp slot. (Contributed by Mario Carneiro, 25-Oct-2015) (New usage is discouraged.)

	Ref	Expression
Assertion	ocndx	⊢ ( oc ‘ ndx ) = ; 1 1

Proof

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