A N. Bourbaki type general theory and the properties of contracting symbols and corresponding contracted forms.
About the sixth Hilbert's problem
Abstract linear dependence.
An axiom system for full -dimensional Euclidean geometry
We present an axiom system for class of full Euclidean spaces (i.e. of projective closures of Euclidean spaces) and prove the representation theorem for our system, using connections between Euclidean spaces and elliptic planes.
An axiom system for incidence spatial geometry.
Incidence spatial geometry is based on three-sorted structures consisting of points, lines and planes together with three intersort binary relations between points and lines, lines and planes and points and planes. We introduce an equivalent one-sorted geometrical structure, called incidence spatial frame, which is suitable for modal considerations. We are going to prove completeness by SD-Theorem. Extensions to projective, affine and hyperbolic geometries are also considered.
An Axiomatics for Hyperbolic Projective-Metric Planes in Terms of Lines and Orthogonality
Hyperbolic projective-metric planes, first axiomatized by R. Lingenberg [7], are shown to be axiomatizable in terms of lines and orthogonality.
Axiomatization and undecidability results for linear betweenness relations