Research Laboratory of Shimizu Construction Co.,Ltd (Institute of Technology, Shimizu Corporation), Tokyo 104, Japan
(Received July 1, 1990; Accepted November 1, 1990)
Abstract. Planar configurations consisting of n straight lines, finite or infinite, and dividing the plane into n+l parts are considered, where the relation "making letter T" is basic. Symbolism for such T-configurations of orthogonal case and their realization with canonical size are described.