Box is related to Item. Item is related to Clock. Clock is related to Hour. Hour is related to Measurement. 
Gap is a type of Dispute. Gap is related to Distance. Distance is related to Reach. Reach is related to Extent. 
Box <--RelatedTo--> Item <--RelatedTo--> Clock <--RelatedTo--> Hour <--RelatedTo--> Measurement 
Dispute <--IsA-- Gap <--RelatedTo--> Distance <--RelatedTo--> Reach <--RelatedTo--> Extent 