Rival is a type of Compete. Rival is related to Enemy. Enemy is related to Bomb. Bomb is related to Explosion. 
Assign is a type of Judge. Judge is the opposite of Criminal. 
Compete <--IsA-- Rival <--RelatedTo--> Enemy <--RelatedTo--> Bomb <--RelatedTo--> Explosion 
Assign --IsA--> Judge <--Antonym--> Criminal 