Democracy is related to System. System is related to Door. Door is related to Item. Tool is a type of Item. 
Calculation is a type of Procedure. Procedure is related to Court. Court is related to Sport. Baseball is a type of Sport. 
Democracy <--RelatedTo--> System <--RelatedTo--> Door <--RelatedTo--> Item <--IsA-- Tool 
Calculation --IsA--> Procedure <--RelatedTo--> Court <--RelatedTo--> Sport <--IsA-- Baseball 