Decrease is the opposite of Rise. Rise is related to Present. Present is related to Ring. Toll is a type of Ring. 
Struggle is a synonym of Try. Try can be used for Do. Do is related to Crawl. 
Decrease <--Antonym--> Rise <--RelatedTo--> Present <--RelatedTo--> Ring <--IsA-- Toll 
Struggle <--Synonym--> Try --UsedFor--> Do <--RelatedTo--> Crawl 