Bank is a type of Array. Bank is related to Federal. Federal is similar to Northern. 
Area is a type of Structure. Area is related to Size. Size is related to Abstract. Abstract is a type of Concept. 
Array <--IsA-- Bank <--RelatedTo--> Federal <--SimilarTo--> Northern 
Structure <--IsA-- Area <--RelatedTo--> Size <--RelatedTo--> Abstract --IsA--> Concept 