Sail is related to White. White is related to Envelope. Envelope is a type of Bag. Bag can be used for Traveler. 
Fly is related to Can. Can is a synonym of Toilet. 
Sail <--RelatedTo--> White <--RelatedTo--> Envelope --IsA--> Bag --UsedFor--> Traveler 
Fly <--RelatedTo--> Can <--Synonym--> Toilet 