Theorem dsndx

Description: Index value of the df-ds slot. (Contributed by Mario Carneiro, 14-Aug-2015) (New usage is discouraged.)

	Ref	Expression
Assertion	dsndx	$$⊢\mathrm{dist}\left(\mathrm{ndx}\right)=12$$

Proof

Step	Hyp	Ref	Expression
1		df-ds	$$⊢\mathrm{dist}=\mathrm{Slot}12$$
2		1nn0	$$⊢1\in {\mathbb{N}}_0$$
3		2nn	$$⊢2\in \mathbb{N}$$
4	2 3	decnncl	$$⊢12\in \mathbb{N}$$
5	1 4	ndxarg	$$⊢\mathrm{dist}\left(\mathrm{ndx}\right)=12$$