premise: Perhaps the Proximity people thought that they had got round that little problem by giving the same definition for each of the items in the list ; but we know that only very rarely are two synonyms bi-unique ( which is another way of saying that if A = B , B does not necessarily always equal A ) , an ineluctable fact of language and true is true and true is true and true is true and true is true and true is true .
hypothesis: X and Y are always the exact same thing .