Monthly Archives: October 2008


   Malawi Here are two additional sectionettes from my “Notices of the AMS” book review entitled “Economic and Common Sense” on Steven Landsburg’s book “More Sex is Safe Sex – the unconventional wisdom of economics”.  Both sectionettes deal with Government intervention in economics. The first is about fertilizer … Continue reading

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Two Math Riddles

Usually I am not particularly good at telling math riddles or solving them, and I was not planning on presenting math riddles here. But these days, when mathematical blogs break new ground and enter uncharted territories, let me make an exception and tell you … Continue reading

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About Mathematics

This post collects some brief philosophical thoughts about mathematics that appeared as part of my paper “Combinatorics with a geometric flavor: some examples,” from the proceedings of the conference “Vision in Mathematics, towards 2000.” I added two small items (the first and … Continue reading

Posted in Philosophy, What is Mathematics | Tagged | 6 Comments

Extremal Combinatorics IV: Shifting

  Compression   We describe now a nice proof technique called “shifting” or “compression” and mention a few more problems.   The Sauer-Shelah Lemma: Let . Recall that a family shatters a set if for every there is   such that … Continue reading

Posted in Combinatorics, Open problems | Tagged , | 4 Comments

Stand Clear of The Closing Doors, Please

Do you miss New York City? Here is something to remind you click here click also  here (video) One more time? Click here.     London lovers, however, say that this is nothing compared to

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