Shell is a type of Remove. Removal is derived from Remove. Withdrawal is a type of Removal. 
Window is a type of Film. Fog is a type of Film. Fog is related to Head. Head is a synonym of Category. 
Shell --IsA--> Remove <--DerivedFrom-- Removal <--IsA-- Withdrawal 
Window --IsA--> Film <--IsA-- Fog <--RelatedTo--> Head <--Synonym--> Category 