> On Feb 5, 6:10 am, "T.H. Ray" <thray...@aol.com> > wrote: > > > The informal explanation does not contradict the > formal > > description of a function as a single valued total > > relation between sets > > The various informal explanations are incompatible > with the formal set > theoretical definition, each in at least one > important sense, which > has been discussed over and over again already in > this thread. > > MoeBlee > > > We may have different ideas of what constitutes an important sense.
Speaking only for my own characterization, I find no conflict between the set theoretic definition and mine. Granted, the formal definition incorporates both necessary and sufficient conditions, while I give only a sufficient condition. However, what is sufficient for a 12 year old will not obviate her search for the necessary, should she have the ambition.