Cross-Ratios over the geometric structures which are coordinatized with alternative or local alternative rings

Abstract

In this notc we summarize [3], [4] and [9] which are intercsted with cross ratio över alternative or local alternative rings. In [9 ], there is an algebraic cxpression which is not true [6], [7]. For this, we give some proofs by using formal calculations. And wc give some basic results which are useful for calculations.