Course is related to Credit. Credit is the opposite of Debt. Debt is the opposite of Asset. Asset is a type of Possession. 
Door can be Large. Door is related to Square. Square is related to Picture. 
Course <--RelatedTo--> Credit <--Antonym--> Debt <--Antonym--> Asset --IsA--> Possession 
Large <--HasProperty-- Door <--RelatedTo--> Square <--RelatedTo--> Picture 