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MVLSC 42.4, p. 375-383
MVLSC Home · Issue Contents · Forthcoming Papers Remarks on Antichains in the Causality Order of Space-time Stephan Foldes We study partial orders defined on the set of points of space-time that are invariant under Lorentz transformations. Kirszbraun’s Theorem allows to show that world lines of particles evolving in space-time are precisely the maximal […]
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MVLSC 42.4, p. 349-373
MVLSC Home · Issue Contents · Forthcoming Papers Description of the Digraphs {−1}-hypomorphic to a Reducible Digraph Mouna Achour, Youssef Boudabbous and Abderrahim Boussaïri Let 𝐺 be a digraph with vertex set 𝑉. A module of 𝐺 is a set 𝑀 of vertices indistinguishable by the vertices outside 𝑀. A module of 𝐺 distinct […]
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MVLSC 42.4, p. 333-348
MVLSC Home · Issue Contents · Forthcoming Papers Prime and Critical Digraphs Mayssam Barhoumi, Jamel Dammak and Hamza Si Kaddour Given a digraph 𝐺 = (𝑉, 𝐸), a subset 𝑀 of 𝑉 is a module of 𝐺 if for 𝑎 ≠ 𝑏 ∈ 𝑀 and 𝑥 ∈ 𝑉 \ 𝑀, (𝑎, 𝑥) ∈ 𝐸 (resp. […]
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MVLSC 42.4, p. 299-331
MVLSC Home · Issue Contents · Forthcoming Papers Siblings of Countable Cographs Geňa Hahn, Maurice Pouzet and Robert Woodrow We show that every countable cograph has either one or infinitely many siblings. This answers, very partially, a conjecture of Thomass´e. The main tools are the notion of well quasi-ordering and the correspondence between cographs […]
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