The Mathematics of an Inheritance System, based on Weighted Inheritance Networks, with a Profitable view of multiple extensions C.T.I. Technical Report TR 93.09.35 - Βουτσινάς, Βασίλειος; Σταματίου, Ι. (Computer Technology Institute Computer Science and Engineering Department, Patras University Ινστιτούτο Τεχνολογίας Υπολογιστών, 1993)