Cash is a type of Exchange. Cash is related to Unit. Couple is a type of Unit. 
Staff is a type of Serve. Staff is related to Musical. Fame is a type of Musical. Fame is etymologically related to Ban. 
Exchange <--IsA-- Cash <--RelatedTo--> Unit <--IsA-- Couple 
Serve <--IsA-- Staff <--RelatedTo--> Musical <--IsA-- Fame --EtymologicallyRelatedTo--> Ban 