Bread is related to Square. Square is a different concept from Round. Round is related to Tire. Tired is a form of Tire. 
Cover is related to Roof. Roof is related to Ceiling. 
Bread <--RelatedTo--> Square <--DistinctFrom--> Round <--RelatedTo--> Tire <--FormOf-- Tired 
Cover <--RelatedTo--> Roof <--RelatedTo--> Ceiling 