Change is a type of Thing. Variable is a type of Thing. 
Pistol can be used for Shoot. Pistol can Wound. Wound is related to Type. Type is related to Duty. 
Change --IsA--> Thing <--IsA-- Variable 
Shoot <--UsedFor-- Pistol --CapableOf--> Wound <--RelatedTo--> Type <--RelatedTo--> Duty 