As a foreword, here we publish an email letter of Late Professor Herb Simon, Nobel Laureate, that he wrote on the occasion of the death of the fatherofa friend. This letterofcondolence, more than any other wisdom, tells about the essence of the process of scientific creation, which is so important for both, the specific subject being covered by this book, and for the general science. When asked to address an SSGRR conference in Italy, prior to his death, Professor Herb Simon agreed that these lines be presented to all those who are interested in understanding the real essence of their own scientific struggle. Dear Professor Milutinovic: I want to extend my deepest sympathy to you and your family on the death of your father. His career was a very distinguished one, and his life spanned a most complex and difficult sequence of epochs in your country's history. Our generation (I am just a year younger than he was), like all its predecessors, leaves many tasks - hopefully no more than it inherited - for the next generation to take up; but even knowing that it must be so does not remove one's senseofloss in the parting.