Nurse is related to Worker. Investor is a type of Worker. Bear is a type of Investor. Bear is related to Mean. 
Internet can be Useful. Internet is related to Post. Post is a type of Product. 
Nurse <--RelatedTo--> Worker <--IsA-- Investor <--IsA-- Bear <--RelatedTo--> Mean 
Useful <--HasProperty-- Internet <--RelatedTo--> Post --IsA--> Product 