Noetherscher Ring/Positive Charakteristik/Existenz der Hilbert-Kunz-Multiplizität/en/Fakt

Let ${}K$ denote a field of positive characteristic ${}p$ , let ${}K\subseteq R$ be a noetherian ring and let ${}I\subseteq R$ be an ideal which is primary to some maximal ideal. Then the Hilbert-Kunz multiplicity ${}e_{HK}(I)$ exists and is a positive real number.