Button is a type of Artifact. Button is related to Push. Push is related to Blow. Blow is a synonym of Cocaine. 
Servant is a type of Worker. Scientist is a type of Worker. 
Artifact <--IsA-- Button <--RelatedTo--> Push <--RelatedTo--> Blow <--Synonym--> Cocaine 
Servant --IsA--> Worker <--IsA-- Scientist 