Abstract
It was shown by P.Dembowski [1;Satz 3] that any finite semiaffine plane(=FSAP) is of the types:
-
(I)
A finite affine plane,
-
(II)
A finite projective plane with one line and all its points except one deleted,
-
(III)
A finite projective plane with one point deleted,
-
(IV)
A finite projective plane.
This was established by using the results obtained for natural parallelisms of incidence structures. The purpose of this note is to give a new proof based on purely combinatorial arguments.
Similar content being viewed by others
References
P. Dembowski; Semiaffine Ebenen. Arch. Math. XIII (1962), 120–131.
P. Dembowski; Finite Geometries,Springer-Verlag, New York 1968.
P. de Witte; Combinatorial Properties of Finite Linear Spaces I. Bull. Soc. Math. de Belgique XVIII (1966), 133–141.
P. de Witte; A New Property of Non-trivial Finite Linear Spaces. Bull. Soc. Math. de Belgique XVIII (1966), 430–438.
G. Pickert; Projektive Ebenen, Springer-Verlag, Berlin-Göttingen-Heidelberg 1955.
Author information
Authors and Affiliations
Additional information
The author was supported by the National Research Council of Canada.
Rights and permissions
About this article
Cite this article
Farrahi, B. A new proof of a theorem of Dembowski. J Geom 5, 185–189 (1974). https://doi.org/10.1007/BF01949681
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01949681