From: Leland McInnes on
On Jun 15, 5:00 pm, Transfer Principle <lwal...(a)lausd.net> wrote:
> On Jun 12, 8:24 am, Aatu Koskensilta <aatu.koskensi...(a)uta.fi> wrote:
>
> > Transfer Principle <lwal...(a)lausd.net> writes:
> > > The response I'd like to see is one which defends classical analysis
> > > against these smooth infinitesimals
> > This idea, that classical analysis needs defending against smooth
> > infinitesimals, is bizarre.
>
> But there has to be a reason why most mathematicians use
> classical analysis and not smooth infinitesimal analysis.

I expect that relative newness of SIA is a big part. To make robust
foundations for SIA possible you need to ground things in topos theory
with its more flexible logics. That meant that SIA wasn't developed as
a theory until the 1980s. Compare that to classical calculus which has
more then a centurey of established history.

> I thought the fact that the latter contradicts the Law of
> the Excluded Middle was one reason to reject it. If not,
> then I'd like to see some of the real reasons that the
> classical analyis is more prevalent -- and once again,
> without the use of five-letter insults.

Because classical analysis is well established and has been around a
long time. SIA is very new and requires some deep mqathematics to
fully ground it, so it doesn't get taught. I think that's most of the
reasons.