Boy is related to Family. Family is related to Other. Other is related to Brother. Brother is a type of Friend. 
Vegetable is related to Potato. Potato is related to Sack. 
Boy <--RelatedTo--> Family <--RelatedTo--> Other <--RelatedTo--> Brother --IsA--> Friend 
Vegetable <--RelatedTo--> Potato <--RelatedTo--> Sack 