Butter is related to Animal. Animal is related to Barn. you are likely to find Cat in/at/on Barn. 
Assign is a type of Transfer. Send is a type of Transfer. Send is related to Birthday. 
Butter <--RelatedTo--> Animal <--RelatedTo--> Barn <--AtLocation-- Cat 
Assign --IsA--> Transfer <--IsA-- Send <--RelatedTo--> Birthday 