P S A previous comment on this talk page gives a quotation worded identically to the first sentence of the article s history section as it stood at the time and says This is a statement in Florian Cajori s history I initially took this to mean that the quotation was alleged to have appeared verbatim in that work of Cajori s I now suspect that I was mistaken and that it was merely intended to assert that something roughly synonymous appears in Cajori s history At any rate although Cajori does say in the fifth edition of his history that Hippolytus knew about casting out nines he does not appear to have anywhere mentioned the expression abjectio novenaria