On Jan 11, 10:50 am, Dan Christensen <Dan_Christen...@sympatico.ca> wrote:
> They seem to > believe that you can do serious work in group theory without any > reference to an underlying set or even set membership. > (I really hope > I am wrong about this.)
You keep saying "seem" this and "seem" that. I didn't opine as to "serious work". If you wish to mention my remarks, then please stick to what I've actually said. I've asked you this a few times already.
> They can't talk about subgroups even in the > abstract,
I do that, formally, in set theory, or informally in general mathematics that includes the study of various algebras such as groups.