    Sentence F 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 rardy are two  synonyms bi-unique (which is another way  of saying that if A = B, B does not  necessarily dways equd A). an ineluctable  Fact of Iéhguage.    Sentifnae 2- X and Y are dways the exact  same thing.