Main is related to Pipe. Pipe is related to Implement. Implement is a synonym of Enforce. 
Injure is related to Wound. you are likely to find Wound in/at/on War. War is related to Game. 
Main <--RelatedTo--> Pipe <--RelatedTo--> Implement <--Synonym--> Enforce 
Injure <--RelatedTo--> Wound --AtLocation--> War <--RelatedTo--> Game 