Clojure's Solutions to the Expression Problem Discussion on LtU

Martin Odersky's comment

"I'm mystified. The expression problem is about adding data variants and operations to a system while statically ensuring that all operations can deal with all variants. How does that even make sense in a dynamically typed language like Clojure? "

set off a discussion on whether the problem solved in the talk is actually the expression problem. Interesting reading.

Ralf Laemmel three videos explain the expression problem in some detail for anyone interested. (start here http://channel9.msdn.com/Shows/Going+Deep/C9-Lectures-Dr-Ral...)