Possession is a type of District. District is related to County. 
Grandfather is a type of Grandparent. Grandfather is a different concept from Grandmother. Grandmother is related to Elderly. Elderly is a synonym of Senior. 
Possession --IsA--> District <--RelatedTo--> County 
Grandparent <--IsA-- Grandfather <--DistinctFrom--> Grandmother <--RelatedTo--> Elderly <--Synonym--> Senior 