[RESOLVED] F Brainfck Interpreter (F#)

Attached to this thread is an interpreter for a minimalist programming language called Brain***** designed by Urban Müller. It only has eight different commands. The interpreter I made for it can load and execute files containing source code for the language.

Wikipedia has more information, but due to the language's somewhat offensive name part of the url is censored by this forum so I can't post a direct link. Just search for "Urban Müller" and you should be able to find it.

Notes:
-I wrote this same program in several other languages (vb6, vb.net, C++) and posted those on vbforums.com as well.

I don't have a lot of experience with F#, so if any one has suggestions for improvements, please let me know.

The program has been mostly rewritten since first posted on this forum so that it's coding style is now mostly functional. However, there are still a few mutable variables (about 6) and a few loops (about 2 or 3.) If any one has any ideas on how to rewrite those bits to better fit a functional style of coding, I would like to hear them. :-) Thanks in advance.

It seems that I managed to remove all imperative loops and mutable values.