Cookie is a type of Dessert. Chocolate is a type of Dessert. Chocolate is related to Day. Day is related to Office. 
Invention is related to Discover. Discover is related to World. World is a type of Class. 
Cookie --IsA--> Dessert <--IsA-- Chocolate <--RelatedTo--> Day <--RelatedTo--> Office 
Invention <--RelatedTo--> Discover <--RelatedTo--> World --IsA--> Class 