Middle is related to Medium. Medium is related to Art. you are likely to find Art in/at/on Fair. Fair is related to Equal. 
Incentive would make you want to Perform. Perform is related to Act. Role can be used for Act. 
Middle <--RelatedTo--> Medium <--RelatedTo--> Art --AtLocation--> Fair <--RelatedTo--> Equal 
Incentive --CausesDesire--> Perform <--RelatedTo--> Act <--UsedFor-- Role 