Retail is related to Sale. Sale is related to Market. Market is related to Vegetable. Vegetable is related to Tree. 
Weigh is related to Scale. Scale is related to Foot. 
Retail <--RelatedTo--> Sale <--RelatedTo--> Market <--RelatedTo--> Vegetable <--RelatedTo--> Tree 
Weigh <--RelatedTo--> Scale <--RelatedTo--> Foot 