MVC within Keel

Hello:

I was looking at the app-hoj example application. I am
just wondering if putting "commands" within the code
of model puts the M & C of MVC within the model of
keel. Should we have another set of classes as pure
busines layers? Can you please point me to wiki that
clarifies it (if any). I am just confused if we are
restricted to the same controller sequence which is
hardcoded within the code of model. 

Thanks for your help.

-shovon-