Position is a type of Assumption. Direction is a type of Position. Direction is related to Line. Line is related to Array. 
Return is a synonym of Depict. Depict is a synonym of Register. Register is part of Memory. 
Assumption <--IsA-- Position <--IsA-- Direction <--RelatedTo--> Line <--RelatedTo--> Array 
Return <--Synonym--> Depict <--Synonym--> Register --PartOf--> Memory 