# Sum of Sequence inside a replace rule? [duplicate]

I'd like a replacement rule that replaces derivatives with their total order. I tried

ReplaceAll[Derivative[x__] -> Plus[x]][Derivative[1, 1]]


but it doesn't return 2, but Sequence[1,1].

How could I get the sum of the sequence to work inside the rule?

• RuleDelayed instead of Rule. – Carl Woll Sep 15 '17 at 17:15

ReplaceAll[Derivative[x__] :> Plus[x]][Derivative[1, 1]]