A Class of Translation Planes of Order 3...
A classification of finite homogeneous semilinear spaces.
A combinatorial approach to the known projective planes of order nine
A combinatorial characterization of finite projective planes using strongly canonical forms of incidence matrices is presented. The corresponding constructions are applied to known projective planes of order 9. As a result a new description of the Hughes plane of order nine is obtained.
A combinatorial theory of Grünbaum's new regular polyhedra, Part II: Complete enumeration.
A combinatorial theory of Grünbaum's new regular polyhedra, Part I: Grünbaum's new regular polyhedra and their automorphism group.
A Cone of Inhomogeneous Second-Order Polynomials.
A conjecture of Stein on plane dissections.
A consistency equation for three geometries.
A Construction of a Skewaffine Structure in Laguerre Geometry
J. Andre constructed a skewaffine structure as a group space of a normally transitive group. In this paper his construction is used to describe the structure of the set of circles not passing through a point of a Laguerre plane. Sufficient conditions to ensure that this structure is a skewaffine plane are given.
A coordinatization of generalized quadrangles of order , .
A course in spatial visualisation.
A De Bruijn-Erdős theorem for - metric spaces
A special case of a combinatorial theorem of De Bruijn and Erdős asserts that every noncollinear set of points in the plane determines at least distinct lines. Chen and Chvátal suggested a possible generalization of this assertion in metric spaces with appropriately defined lines. We prove this generalization in all metric spaces where each nonzero distance equals or .
A decomposition of a set definable in an o-minimal structure into perfectly situated sets
A definable subset of a Euclidean space X is called perfectly situated if it can be represented in some linear system of coordinates as a finite union of (graphs of) definable 𝓒¹-maps with bounded derivatives. Two subsets of X are called simply separated if they satisfy the Łojasiewicz inequality with exponent 1. We show that every closed definable subset of X of dimension k can be decomposed into a finite family of closed definable subsets each of which is perfectly situated and such that any...
A Desarguesian dual for Nagel's middlespoint.
A family of complete arcs in finite projective planes
A family of conics and three special ruled surfaces.
A family of flat Minkowski planes admitting 3-dimensional simple groups of automorphisms.
A Family of Impossible Figures Studied by Knot Theory
A family of Minkowski planes over half-ordered fields.
A Family of Not (V, l)-Transitivity Projective Planes of Order q3, q ... 1 (mod 3) and q ... 2.