7
votes
6answers
1k views

How do you present a non-existence theorem?

(This question might be too vague, feel free to edit or vote for closing.) In math there are usually lots of non-existence theorems. When someone presents such a theorem, one natural response is "why ...
16
votes
14answers
2k views

Teaching a pedagogy course

At my institution incoming graduate students must take a semester long course on pedagogy taught by current grad students. I may soon be in the position of having to teach this course and I'm looking ...
17
votes
6answers
853 views

How should one present calculations?

It is often necessary to present calculations, or at least their outlines, in a proof. However, when I need to do it, if the calculation takes more than one line (or perhaps two at the most), I feel ...
1
vote
2answers
318 views

Use of the word “data” not in the statistical sense [closed]

Occasionally I see the use of the word "data" in definitions. For instance, one definition of an exact sequence starts off by saying, "An exact sequence of abelian groups (or modules or vector spaces) ...