An oddity in list comparison and element assignment

[Terry Hancock]

Alex Martelli wrote:
>  Slawomir Nowaczyk <slawomir.nowaczyk.847 at student.lu.se> wrote:
> > On Thu, 01 Jun 2006 13:40:34 -0700 michael.f.ellis at gmail.com wrote:
> > #> Scott David Daniels wrote: #> > Would you say that envelope
> > containing five $100 bills is equal to #> > an envelope containing
> > five $100 bills with different serial numbers?
> >
> > #> Yes (unless I was testing the assertion that the second envelope
> > did #> not contain counterfeits of the first)
> >
> > So, what if Bank of America later decided that bills with serial
> > numbers containing "7" are no longer valid?
>
>  Then Wachowia would no doubt be happy to take my business away from
>  BoA;-).
>
>  I suspect you believe BoA is some kind of "official" body -- it
>  isn't, just like Deutschebank is not one in Germany (rather,
>  Bundesbank is).

Yeah, it's a funny mistake, but what he meant, is what if the
US Treasury Department declared bills with serial numbers
containing "7" invalid.  That would indeed complete the analogy.

And it's a sharp example -- because money is conceived of as
fungible, one $100 is as good as another, so two $100 bills
compare as equal, whether they are equal or not.

Of course, the counter argument is that it's not unlike  counting
a reflection of a $100 bill as another $100 and concluding that
you have $200 (you need two mirrors to double your money,
technically ;-)).

I don't think there's any way to make it "more logical" -- it's
going to break somewhere no matter what assumption you
make, so you just have to learn what's really going on in order
to avoid confusion.

Cheers,
Terry



-- 
Terry Hancock (hancock at AnansiSpaceworks.com)
Anansi Spaceworks http://www.AnansiSpaceworks.com