Gate is a type of Gross. you are likely to find Gate in/at/on Backyard. 
Island is related to Mass. Mass is related to Value. Value is related to Good. Good is related to Sale. 
Gross <--IsA-- Gate --AtLocation--> Backyard 
Island <--RelatedTo--> Mass <--RelatedTo--> Value <--RelatedTo--> Good <--RelatedTo--> Sale 