On 10/25/07, Matej Kosik <kosik@fiit.stuba.sk> wrote:
  

I am sorry. This wasn't the proper word.

Certainly, I believe that there are things that cannot be modelled in the pure functional language
(whose constructs can be without exceptions mapped to the lambda-calculus). This is not only the
case of input/output. This is also the case of modelling stateful systems that interact with their
environment over time (not only at the beginning and at the end). So pretending that functional
programming can cover all the important aspects of systems we need to model is unfaithful. Those
impurities are useful.
    

Um, you are aware that lambda-calculus is Turing equivalent right?

http://en.wikipedia.org/wiki/Turing-complete

"The untyped lambda calculus is Turing-complete, but many typed lambda
calculi, including System F, are not."