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.
Perhaps people got around that problem by giving the same definition for each item on the list but we know that two items are very rarely bi-unique and not a fact of language.