Ulam's pathological liar game with one half-lie

We introduce a dual game to Ulam's liar game and consider the case of one half-lie. In the original Ulam's game, Paul attempts to isolate a distinguished element by disqualifying all but one of n possibilities with q yes-no questions, while the responder Carole is allowed to lie a fixed nu...

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Bibliographic Details
Main Authors: Robert B. Ellis, Catherine H. Yan
Format: Article
Language:English
Published: Hindawi Limited 2004-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Online Access:http://dx.doi.org/10.1155/S0161171204306204
Description
Summary:We introduce a dual game to Ulam's liar game and consider the case of one half-lie. In the original Ulam's game, Paul attempts to isolate a distinguished element by disqualifying all but one of n possibilities with q yes-no questions, while the responder Carole is allowed to lie a fixed number k of times. In the dual game, Paul attempts to prevent disqualification of a distinguished element by pathological liar Carole for as long as possible, given that a possibility associated with k+1 lies is disqualified. We consider the half-lie variant in which Carole may only lie when the true answer is no. We prove the equivalence of the dual game to the problem of covering the discrete hypercube with certain asymmetric sets. We define A1*(q) for the case k=1 to be the minimum number n such that Paul can prevent Carole from disqualifying all n elements in q rounds of questions, and prove that A1*(q)~2q+1/q.
ISSN:0161-1712
1687-0425