منابع مشابه
Octants are Cover Decomposable
We prove that octants are cover-decomposable, i.e., any 12-fold covering of any subset of the space with a finite number of translates of a given octant can be decomposed into two coverings. As a corollary, we obtain that any 12-fold covering of any subset of the plane with a finite number of homothetic copies of a given triangle can be decomposed into two coverings. We also show that any 12-fo...
متن کاملOctants are cover-decomposable into many coverings
We prove that octants are cover-decomposable into multiple coverings, i.e., for any k there is an m(k) such that any m(k)-fold covering of any subset of the space with a nite number of translates of a given octant can be decomposed into k coverings. As a corollary, we obtain that any m(k)-fold covering of any subset of the plane with a nite number of homothetic copies of a given triangle can be...
متن کاملCyclically Indecomposable Triple Systems that are Decomposable
Cyclically Indecomposable Triple Systems that are Decomposable Martin Grüttmüller Institut für Mathematik, Universität Rostock In this talk, we construct, by using Skolem-type and Rosa-type sequences, cyclically indecomposable two-fold triple systems TS2(v) for all admissible orders. We also investigate exhaustively the cyclically indecomposable triple systems TSλ(v) for λ = 2, v ≤ 33 and λ = 3...
متن کاملVarieties Whose Tolerances Are Homomorphic Images of Their Congruences
The homomorphic image of a congruence is always a tolerance (relation) but, within a given variety, a tolerance is not necessarily obtained this way. By a Maltsev-like condition, we characterize varieties whose tolerances are homomorphic images of their congruences (TImC). As corollaries, we prove that the variety of semilattices, all varieties of lattices, and all varieties of unary algebras h...
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We prove that all connected vertex-transitive graphs of order p, p a prime, can be decomposed into Hamilton cycles.
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ژورنال
عنوان ژورنال: Czechoslovak Mathematical Journal
سال: 1990
ISSN: 0011-4642,1572-9141
DOI: 10.21136/cmj.1990.102394