Sum of Sequence inside a replace rule?

Question

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 — Carl Woll, Sep 15 '17 at 17:15

score 1 · Accepted Answer · answered Sep 15 '17 at 17:17

1

As per the comment above,

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

answered Sep 15 '17 at 17:17

Sampo Smolander

1 Answers1