Metamath Proof Explorer


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 11
2 1nn0 ⊢ 1 ∈ ℕ 0
3 1nn ⊢ 1 ∈ ℕ
4 2 3 decnncl ⊢ 11 ∈ ℕ
5 1 4 ndxid ⊢ oc = Slot oc ⁡ ndx