1. An artificial neural network having a plurality of neurons adapted to associate a complex component operator to each of a plurality of components of an input pattern in the process of evaluating a final distance between the input pattern and a plurality of prototypes stored in the neurons of the artificial neural network comprising: data-in transmitting means for applying input pattern components to each of the neurons; storage means to store and apply a plurality of complex component operators to each of the neurons via a bus, wherein each of the complex component operators has a function and at least one parameter attached thereto; said plurality of neurons in which each of the neurons has a prototype memory to store a plurality of components of a prototype and distance evaluation means connected to said prototype memory, to said storage means via said bus and to said data-in transmitting means; addressing means for applying the input pattern components, the corresponding one of the plurality of complex component operators associated therewith and the corresponding stored prototype component to said distance evaluation means in each of the neurons; means for applying a distance norm to the distance evaluation means; wherein said distance evaluation means are adapted to perform an elementary distance calculation between the corresponding components of the input pattern and the stored prototype using the corresponding complex component operator associated thereto for each component, said complex component operator being obtained by decoding of said function and processing of said at least one parameter and said distance evaluation means is also adapted to combine said calculated elementary distance to determine the final distance using said distance norm.