Thank you very much for your help. Very concisely.Russian say: brevity is the sister of talent. I made my own naive solution which based on VoidEx's advise. In Russian, but I think, you'll see the idea. It has some noise such as CLazyList what is no more than code atavism from previous versions.

2011/12/16 Edward Z. Yang <ezyang@mit.edu>

I did a writeup for an even simpler example, which hopefully will give you the
right idea how to do it in your case:

http://blog.ezyang.com/2011/12/accessing-lazy-structures-from/

Cheers,
Edward