Metamath Proof Explorer


Theorem dsid

Description: Utility theorem: index-independent form of df-ds . (Contributed by Mario Carneiro, 23-Dec-2013)

Ref Expression
Assertion dsid dist = Slot ( dist ‘ ndx )

Proof

Step Hyp Ref Expression
1 df-ds dist = Slot 1 2
2 1nn0 1 ∈ ℕ0
3 2nn 2 ∈ ℕ
4 2 3 decnncl 1 2 ∈ ℕ
5 1 4 ndxid dist = Slot ( dist ‘ ndx )