Cycle is a type of Series. Cycle is related to Gentle. Gentle is a synonym of Friendly. Friendly is the opposite of Enemy. 
Rail is a type of Bar. Rail is related to Road. 
Series <--IsA-- Cycle <--RelatedTo--> Gentle <--Synonym--> Friendly <--Antonym--> Enemy 
Bar <--IsA-- Rail <--RelatedTo--> Road 