For example, let denote the OMP associated with the scenario model that contains three logistic population growth models (), two Holling predation model () and one competition model (). Therefore,

and hence:

By describing OMPs as functions, the concept of combinations of OMPs becomes clear. For two OMPs and , the combined preference is defined as:

Note that the combination operator is assumed to be commutative, associative and strictly monotonic ( ). The latter assumption is made to better reflect the ideas underpinning conventional utility calculi [1].