Date: Mar 28, 2013 8:45 PM
Author: fom
Subject: Re: Using classes instead of sets

On 3/28/2013 3:54 PM, Ken Pledger wrote:
> In article <19071bf4-69f8-4ce3-94cb-109044e3f323@googlegroups.com>,
> pepstein5@gmail.com wrote:
>

>> .... Classes are allowed to contain other classes after all....
>
>
> Are you confusing members with subclasses? In Paul Halmos's classic
> "How to Write Mathematics", section 14, he suggests using "contain" for
> members and "include" for subsets. That convention may not be not
> widely used, but at least it draws attention to the possible ambiguity
> of "contains".
>
> Ken Pledger.
>


So when I quickly open my calculus book
from so many years ago, ...

"is a subset of" is the same as "is contained in"

I have a feeling that the ambiguity of
this particular colloquialism is here
to stay.

That article is wonderful by the way. I suspect
you already know that.