Webb14 maj 2024 · Theorem 1.1 (, Neumann and Morgenstern) A finite digraph without cycles has a unique kernel. Theorem 1.2 (, Richardson) A finite digraph without cycles of odd length has a kernel. Theorem 1.3 (, Duchet) IfDis a finite digraph such that every cycle of odd length possesses at least two symmetric arcs, thenDis a kernel perfect digraph. WebbON A THEOREM OF RICHARDSON J. R. ISBELL1 Given a set 5 with an irreflexive relation >, define the operators dom and max as follows. For any subset T of S, dom T is the set of all x in 5 such that for some t\nT,t>x; max T= T — dom T. A solution of (S, >) is a subset T of 5 satisfying T = S — dom T.
Theorem -- from Wolfram MathWorld
Webb1 juli 1987 · The following result has apparently been obtained in [2]: If a finite digraph has no circuits of length nk + r for n = 0, 1, 2,... and 0 < r < k, then it has a k-kernel (k ⩾ 2; Richardson's theorem refers to the case k = 2).. The present note shows that the result is not always valid for k > 2 unless an additional condition is imposed, such that the … In mathematics, Richardson's theorem establishes the undecidability of the equality of real numbers defined by expressions involving integers, π, $${\displaystyle \ln 2,}$$ and exponential and sine functions. It was proved in 1968 by mathematician and computer scientist Daniel Richardson of the University of Bath. Specifically, … Visa mer Richardson's theorem can be stated as follows: Let E be a set of expressions that represent $${\displaystyle \mathbb {R} \to \mathbb {R} }$$ functions. Suppose that E includes these expressions: • x … Visa mer • Constant problem – Problem of deciding whether an expression equals zero • Elementary function – Mathematical function • Tarski's high school algebra problem – Mathematical problem Visa mer After Hilbert's tenth problem was solved in 1970, B. F. Caviness observed that the use of e and ln 2 could be removed. Wang later noted that under the same assumptions under which the question of whether there was x with A(x) < 0 was insolvable, the question of whether … Visa mer • Petkovšek, Marko; Wilf, Herbert S.; Zeilberger, Doron (1996). A = B. A. K. Peters. p. 212. ISBN 1-56881-063-6. Archived from the original on … Visa mer • Weisstein, Eric W. "Richardson's theorem". MathWorld. Visa mer multi speed heat pump
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Webb1 aug. 2015 · 2. The page you cite eventually (at least as of 30 July 2015) links to an answer to your question about decidability. An algebraic expression is decidable. This is also the Tarski-Seidenberg theorem. Algebraic expressions plus exp are decidable if Schanuel's conjecture holds. Otherwise, this is unknown. See Tarski's exponential … WebbDas Kolmogorow-Arnold-Moser-Theorem (kurz „KAM-Theorem“) ist ein Resultat aus der Theorie der dynamischen Systeme, das Aussagen über das Verhalten eines solchen Systems unter kleinen Störungen macht.Das Theorem löst partiell das Problem der kleinen Teiler, das in der Störungsrechnung von dynamischen Systemen, insbesondere in der … Webb16 nov. 2014 · Selected Network Theorems for AC Circuits. ET 242 Circuit Analysis II. E lectrical and T elecommunication Engineering Technology Professor Jang. Acknowledgement. Slideshow 6674086 by martena-richardson multi speed rear axle