Process(P1) postively regulates process(P2) iff: P1 initiates P2, or P1 increases the the frequency of initiation of P2 or the magnitude or rate of output of P2.

Chris Mungall

http://purl.obolibrary.org/obo/ro/docs/causal-relations

positively regulates (process to process)

http://purl.obolibrary.org/obo/RO_0002211