A comathematician
is a device for turning cotheorems into ffee

Hi,

I'd like to share some things that I wrote, mostly concerning my studies:

- Some resources useful for studying
about the
bar construction.

- A lecture
I gave about the standard projective and injective model structures on
the category of chain complexes over some ring R. An interesting
point raised is the difference between a projective chain complex and a
chain complex which is level-wise
projective. In addition, it
has a nice listing of the main characterizations of projective and
injective objects in the category of R-modules.

- Here are notes for a lecture I gave in the preparatory
seminar our group had towards the May 2012 Sdot-Yam workshop. It's titled Mackey
Functors, but it's mostly an introduction to G-sets, along with
classification of G-equivariant maps, and the definition of Bredon
Cohomology.

- When I first studied LyX, it took me some effort to get into
it. I wished I had a concise (and short!) paper explaining just the things I needed in order
to begin working, instead of looking into long-long manuals. So here
are some LyX tips I wrote, as a result.
It's LyX source is
available here.

For those who require various diagrams, be it commutative diagrams, braidings, knots, string diagrams and much more -- there is an excellent XY-pic tutorial with an extensive archive of examples accompanied with the code by Aaron Lauda.

In case you are looking for some specific LaTeX symbol, this is a neat tool that can help you find it.

- Also, here are some tips
for
writing Math with Word 2007.
Since the document is in Hebrew, הנה כמה
טיפים
לכתיבת נוסחאות מתמטיות עם וורד 2007.

As before, I'd be glad to hear comments.

- For those interested in a delta-complex structure for RP^3
(3-dimensional real
projective space), my beloved wife Sandra made a neat video
demonstrating one,
following an Algebraic Topology class I had.

Some explanations about the video:

What you see in the video are three stages of the construction: - A double pyramid-like construction; simplices with same name will eventually be identified.
- Now, imagine the two N-labeled simplices are bent towards each other, lying on the same planes as the M-labeled simplices. That's what you see on the central shape.
- In the last, the more ball-like one, identify the L and U simplices to complete RP^3's
construction.

- Here are some class notes I have taken over the years in a bunch of courses.

I can reached on .

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