Relations, coverings, hypergraphs and matroids
Relationships between conbinatorics and 0-simple semigroups.
Relativnullen und reduzible Mengen bei Differenzen von Mengen ganzer Zahlen.
Remark to a problem on 0-1 matrices
Remarks on factorizations in algebraic number fields
Repeated patterns of dense packings of equal disks in a square.
Resolvable Mendelsohn designs with block size 4.
Resolving triple systems into regular configurations.
Restricted and quasi-toral restricted Lie-Rinehart algebras
In this paper, we introduce the definition of restrictable Lie-Rinehart algebras, the concept of restrictability is by far more tractable than that of a restricted Lie-Rinehart algebra. Moreover, we obtain some properties of p-mappings and restrictable Lie-Rinehart algebras. Finally, we give some sufficient conditions for the commutativity of quasi-toral restricted Lie-Rinehart algebras and study how a quasi-toral restricted Lie-Rinehart algebra with zero center and of minimal dimension should be....
Rhombus tilings of a hexagon with two triangles missing on the symmetry axis.
Rigidité des empilements infinis immergés proprement dans le plan et dans le disque
Room designs and one-factorizations.
Rotary polygons in configurations.
RWPRI and flag-transitive linear spaces.