Semi-Pappus configurations; combinatorial generalizations of the Pappus configuration
A class of partial Steiner triple systems generalizing a reduct of the classical Pappus configuration and thus called semi-Pappus configurations is defined. Fundamental geometric properties, in particular, representations and the automorphisms of semi-Pappus configurations and of the convolutions of semi-Pappus configurations and the group C (2) are established.
pappus configuration partial steiner triple system veblen configuration convolution (of a partial steiner triple system and a group) affine space projective space