Developer is a synonym of Designer. Designer is a type of Planner. Planner is a type of Person. Economist is a type of Person. 
Quantity is related to Force. Gravity is a type of Force. 
Developer <--Synonym--> Designer --IsA--> Planner --IsA--> Person <--IsA-- Economist 
Quantity <--RelatedTo--> Force <--IsA-- Gravity 