Not quite actually. Let X denote 'thing is a Woozle', Y denote 'thing is a Twozzie', Z denote 'thing is a Twozzie'. Then X ==> Y ==> Z, so X ==> Z. However, the statements X Y, but not Y <== X). However, if you say X = Y you'd say something like 'All Woozles are Wozzies and all Wozzies are...