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• Great video - thanks for posting. I would really like to see more detailing the relationship between derivatives and the lambda-calculus. Greg even mentioned he has some code that illustrates the concept - could you post a link?

Good stuff as always!

• Even for people with a CS background, this is a great lecture. I didn't realize there were other kinds of computing models (Pointer machines, Kolmogarov machines). He also gave some great algorithm examples that you can't computer (buckets-of-rain) or that are too slow (real arithmetic).

Great start to a very promising series, thank you!

• Brian,

Have you seen Conal Elliot's paper "Beautiful Differnetation"? It doesn't talk about co- or contra-variance, but he does go over a lot of the same differentation you & Erik covered in your paper:

• That does help a lot - thank you!

• Brian,

Hope this post isn't too late. I'm reading through the attached paper and having trouble in the "Transformations, Jacobians" section (and in the example that follows). your definitions of "bold x" and "bold y" look infinitely recursive to me:

x = X . y

y = Y . x

In the example, I find the same thing when defining x1 (squiggle) and x2 (eta). They are defined in terms of y1 (rho) and y2 (theta). y1 and y2 are then defined in terms of x1 and x2!

I am sure I am thinking too operationally here but any enlightment would be appreciated!

Justin

• You seem to be a troll so it's hard to answer in a cooperative spirit. Moving on ...

I'd say these lectures are geared towards people who know  C#, VB.Net, Java,etc. Mapping back to C# helps ground the concepts. Haskell is like alien technology. It can make things a lot clearer (and more relevant) to correlate it with something you already understand. That's kind of true when learning anything new in fact ...

In any case you can always buy the book at a discount and learn Haskell from the ground up. That's what it was written for.

• Some might like my Haskell Cheatsheet at http://cheatsheet.codeslower.com. It's a short reference & mini-tutorial.

OK - done pimping now

Justin

• Let me pimp my Haskell  Cheatsheet, a short syntax reference and minitutorial:

• There is Visual Haskell, but it's very out of date. It targest VS 2005, does not use the Managed Package Framework (i.e., it extends VS using C++ rather than .NET), and its married to a really old version of GHC:

BUT the sources are available and I wish someone would update it ...

Justin

• I would love to see more of this stuff! Please work it in wherever you can.