Theorem mulrndx

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

	Ref	Expression
Assertion	mulrndx	⊢ ( .r ‘ ndx ) = 3

Proof

Step	Hyp	Ref	Expression
1		df-mulr	⊢ .r = Slot 3
2		3nn	⊢ 3 ∈ ℕ
3	1 2	ndxarg	⊢ ( .r ‘ ndx ) = 3