Oil is related to Gold. Gold is related to Claim. Contend is a type of Claim. Contend is a synonym of Dispute. 
Essay is related to Book. Reading requires Book. Eye can be used for Reading. Eye is related to Lens. 
Oil <--RelatedTo--> Gold <--RelatedTo--> Claim <--IsA-- Contend <--Synonym--> Dispute 
Essay <--RelatedTo--> Book <--HasPrerequisite-- Reading <--UsedFor-- Eye <--RelatedTo--> Lens 