Enumeration to define definition of balance equations
type Dynamics = enumeration(DynamicFreeInitial "DynamicFreeInitial -- Dynamic balance, Initial guess value", FixedInitial "FixedInitial -- Dynamic balance, Initial value fixed", SteadyStateInitial "SteadyStateInitial -- Dynamic balance, Steady state initial with guess value", SteadyState "SteadyState -- Steady state balance, Initial guess value");