Software is etymologically related to Hardware. Mail is a type of Software. Mail is related to House. 
Clock is related to Like. Like is related to Dear. Dear is related to Name. Name is related to Count. 
Hardware <--EtymologicallyRelatedTo-- Software <--IsA-- Mail <--RelatedTo--> House 
Clock <--RelatedTo--> Like <--RelatedTo--> Dear <--RelatedTo--> Name <--RelatedTo--> Count 