Theorem eufndx

Description: Index value of the Euclidean function slot. Use ndxarg . (Contributed by Thierry Arnoux, 22-Mar-2025) (New usage is discouraged.)

	Ref	Expression
Assertion	eufndx	$$⊢\mathrm{EuclF}\left(\mathrm{ndx}\right)=21$$

Proof

Step	Hyp	Ref	Expression
1		df-euf	$$⊢\mathrm{EuclF}=\mathrm{Slot}21$$
2		2nn0	$$⊢2\in {\mathbb{N}}_0$$
3		1nn	$$⊢1\in \mathbb{N}$$
4	2 3	decnncl	$$⊢21\in \mathbb{N}$$
5	1 4	ndxarg	$$⊢\mathrm{EuclF}\left(\mathrm{ndx}\right)=21$$