formal levels

[C.Foster@massey.ac.nz]

With reference to the recent discussion of levels, there is a formal theory
of levels.  I have developed it as part of a larger (formal) theory of
strong equivalence of complex systems.  This is a PhD thesis in progress for
Edinburgh University's Centre for Cognitive Science.  It should be 
available *soon*.  Let me know if you want a copy or more information.

C. Foster
CFoster at massey.ac.nz
c/- School of Information Sciences
Massey University
Palmerston North
New Zealand