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Conditional Independences among Four Random Variables II

Published online by Cambridge University Press:  12 September 2008

F. Matúš
Affiliation:
Institute of Information Theory and Automation, Pod vodárenskou věží 4, 182 08 Prague, Czech Republic e-mail: matus@utia. cas.cz

Abstract

Numerous new properties of stochastic conditional independence are introduced. They are aimed, together with two surprisingly trivial examples, at a further reduction of the problem of probabilistic representability for four-element sets, i.e. of the problem which conditional independences within a system of four random variables can occur simultaneously. Proofs are based on fundamental properties of conditional independence and, in the discrete case, on the use of I-divergence and algebraic manipulations with marginal probabilities. A duality question is answered in the negative.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1995

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References

[1]Carnal, E. (1980) Independence conditionnelle permutable. Ann. Inst. Henri Poincaré, 16 3947.Google Scholar
[2]Csiszár, I. (1975) I-divergence geometry of probability distributions and minimization problems. Annals of Probability, 3 146158.CrossRefGoogle Scholar
[3]Csiszár, I. and Körner, J. (1981) Information Theory (Coding Theorems for discrete memoryless systems). Akadmiai Kiad, Budapest.Google Scholar
[4]Dawid, A. P. (1979) Conditional independence in statistical theory (with discussion). J. Roy.Statist. Soc. B 41 131.Google Scholar
[5]Döhler, R. (1980) Zur bedingten Unabhängigkeit zufaälliger Ereignisse (On the conditional independence of random events). Theory Probability Appl. 25 628634.CrossRefGoogle Scholar
[6]Lauritzen, S. L. (1989) Lectures on Contingency Tables. University of Aalborg Press.Google Scholar
[7]Matúš, F. (1991) Abstract functional dependency structures. Theor. Computer Sci. 81 117126.CrossRefGoogle Scholar
[8]Matúš, F. (1992) Ascending and descending conditional independence relations. In Trans. 11th Prague Conf. Information Theory, Statistical Decision Functions and Random Processes. Academia, Prague, Vol. B, 181200.Google Scholar
[9]Matúš, F. (1994) Probabilistic conditional independence structures and matroid theory: background. Int. J. General Systems 22 185196.CrossRefGoogle Scholar
[10]Matúš, F. and Studený, M. (1995) Conditional independences among four random variables I. Combinatorics, Probability and Computing (to appear).Google Scholar
[11]Mouchart, M and Rolin, J. M. (1984) A note on conditional independence with statistical applications. Statistica 44 557584.Google Scholar
[12]Pearl, J. (1988) Probabilistic Reasoning in Intelligent Systems. Morgan Kaufman.Google Scholar
[13]Studený, M. (1992) Structural semigraphoids. Int. J. General Systems 22 207217.CrossRefGoogle Scholar
[14]Van Putten, C. and Van Schuppen, J. H. (1985) Invariance properties of the conditional independence relation. Annals of Probability 13 934945.CrossRefGoogle Scholar
[15]Welsh, D. J. A. (1976) Matroid Theory. Academic Press.Google Scholar