Pin is a synonym of Fall. Fall is related to Action. Action is related to Demand. 
Line is a different concept from Object. Catch is a type of Object. Catch is a synonym of Net. Network is derived from Net. 
Pin <--Synonym--> Fall <--RelatedTo--> Action <--RelatedTo--> Demand 
Line <--DistinctFrom--> Object <--IsA-- Catch <--Synonym--> Net <--DerivedFrom-- Network 