Walking is related to Exercise. Exercise is a different concept from Fat. Butter is a type of Fat. Butter is related to Sandwich. 
Cake is a type of Desert. Desert is a synonym of Lonely. 
Walking <--RelatedTo--> Exercise <--DistinctFrom--> Fat <--IsA-- Butter <--RelatedTo--> Sandwich 
Cake --IsA--> Desert <--Synonym--> Lonely 