Obvious is related to Surprise. Surprise is related to Bow. Bow is a synonym of Compel. 
Outlet is related to Print. Machine can be used for Print. Machine can be used for Dig. 
Obvious <--RelatedTo--> Surprise <--RelatedTo--> Bow <--Synonym--> Compel 
Outlet <--RelatedTo--> Print <--UsedFor-- Machine --UsedFor--> Dig 