Head is a synonym of Understanding. Understanding is related to Agreement. Agreement is a type of Statement. 
Pull is a synonym of Generate. Generation is etymologically related to Generate. Generation is a type of Production. Production is related to Factory. 
Head <--Synonym--> Understanding <--RelatedTo--> Agreement --IsA--> Statement 
Pull <--Synonym--> Generate <--EtymologicallyRelatedTo-- Generation --IsA--> Production <--RelatedTo--> Factory 