Theorem mulrndx

Description: Index value of the df-mulr slot. (Contributed by Mario Carneiro, 14-Aug-2015)

	Ref	Expression
Assertion	mulrndx	$$⊢{\cdot }_{\mathrm{ndx}}=3$$

Proof

Step	Hyp	Ref	Expression
1		df-mulr	$$⊢{\cdot }_{𝑟}=\mathrm{Slot}3$$
2		3nn	$$⊢3\in \mathbb{N}$$
3	1 2	ndxarg	$$⊢{\cdot }_{\mathrm{ndx}}=3$$