Lumping in general

Let us start from outside chemical reaction kinetics, from the theory and practice of modelling in general. Let us suppose that the phenomenon to be described can be characterised by a vector-valued function x of N coordi- 

Such a lumping is only meaningful if the resultant process behaves si iiiarily, with respect to some of its properties. For example, if the original pocerS obeys a differential equation 

Mjth in Af X M matrix R. In this case the lumping is said to be exact, 

In th S case K may even be determined from (4.28), although not necessarily 

It (Tiay also be interesting whether the lumping is proper or not. Linear Inuipii g can be written in the following way  

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