Purpose is related to Heat. Heat is related to State. State is related to Shock. Shock is related to Unexpected. 
Informal is a different concept from Dress. Dress is the opposite of Long. Long is the opposite of Instant. 
Purpose <--RelatedTo--> Heat <--RelatedTo--> State <--RelatedTo--> Shock <--RelatedTo--> Unexpected 
Informal <--DistinctFrom--> Dress <--Antonym--> Long <--Antonym--> Instant 