Expression is related to Dear. Dear is related to Pet. 
Vary is a different concept from Consistent. Consistent is a synonym of Uniform. Uniform is related to Wear. Wear is related to Tie. 
Expression <--RelatedTo--> Dear <--RelatedTo--> Pet 
Vary <--DistinctFrom--> Consistent <--Synonym--> Uniform <--RelatedTo--> Wear <--RelatedTo--> Tie 