Tank is a different concept from Sleeve. Elbow is part of Sleeve. Elbow is related to Nearby. Nearby is similar to Near. 
Sin is a type of Letter. Sin is related to Abstract. 
Tank <--DistinctFrom--> Sleeve <--PartOf-- Elbow <--RelatedTo--> Nearby <--SimilarTo--> Near 
Letter <--IsA-- Sin <--RelatedTo--> Abstract 