Fundamental introduction to discrete mathematics, without knowledge of that it is impossible successfully to engage in an informatics and programming. None of numerous editions on this discipline, going out in Russian language, is read with such pleasure and benefit. In an accessible and very enthralling form an author tells about the fundamental concepts of discrete mathematics - about logic, great numbers, columns, relations and boole functions. Theory is expounded a briefly and illustrated by numerous simple examples, that does her accessible even to the schoolboy. After every head (since the second) the appendix of the described methods is examined to the informatics.Additions in edition in Russian language are sanctified to the actual tasks of theory of the graphs, recursive algorithms, general issue of surplus and tasks of the integer programming.A book will be useful to the students, studying the course of discrete mathematics, and also by all persons interested to get to the technique of writing and verification of correctness of algorithms, including practical programmers-workers.