Projective plane PG(2,23) of Type B1 from a PG(3,23) of type D1

The numbers of lines (points) of the various types are given in the first row (column) of the table following. The notation follows that given for the 3-dimensional geometry.

(B1) Plane with one secant and 3 points of the sub-geometry
  No 1 24 48
No Name s t2 x
3 C0 3,1 1,8 0,0
6 C1 6,1 0,0 1,8
64 C2 0,0 8,3 8,6

The complete design above is a BIBD with λ=1.

As the symmetry between points and lines is lost in the detailed breakdown, different subdesigns are available according to whether points or lines are taken as treatments.


Last Updated on 27/03/2004
By D.H.Rees