Plan is a type of Idea. Plan is related to Scheme. 
Argue is a synonym of Contend. Contend is a synonym of Cope. Cope is a synonym of Deal. Deal is a synonym of Sell. 
Idea <--IsA-- Plan <--RelatedTo--> Scheme 
Argue <--Synonym--> Contend <--Synonym--> Cope <--Synonym--> Deal <--Synonym--> Sell 