Theorem ocid

Description: Utility theorem: index-independent form of df-ocomp . (Contributed by Mario Carneiro, 25-Oct-2015)

	Ref	Expression
Assertion	ocid	⊢ oc = Slot ( oc ‘ ndx )

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	ndxid	⊢ oc = Slot ( oc ‘ ndx )