you are likely to find Seat in/at/on Porch. Porch is related to Chair. 
Plunge is the opposite of Increase. Increase is a synonym of Inflation. Inflation is a type of Expansion. Expansion is a type of Discussion. 
Seat --AtLocation--> Porch <--RelatedTo--> Chair 
Plunge <--Antonym--> Increase <--Synonym--> Inflation --IsA--> Expansion --IsA--> Discussion 