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On the number of threshold functions

  • A.A. Irmatov
Published/Copyright: February 2, 2016
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Abstract

A Boolean function is called a threshold function if its truth domain is a part of the n-cube cut off by some hyperplane. The number of threshold functions of n variables P(2, n) was estimated in [1, 2, 3]. Obtaining the lower bounds is a problem of special difficulty. Using a result of the paper [4], Zuev in [3] showed that for sufficiently large n

P(2, n) > 2n²(1-10/ln n).

In the present paper a new proof which gives a more precise lower bound of P(2, n) is proposed, namely, it is proved that for sufficiently large n

P(2, n) > 2n²(1-7/ln n)P(2, [(7(n-1)ln2)/ln(n- 1)]).

Published Online: 2016-2-2
Published in Print: 1993-1-1

© 2016 by Walter de Gruyter Berlin/Boston

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