D.Mangeron(1), A.M.Krall(
Until recently there were two kinds of orthogonality commonly accepted:that generatedby a real weight function and that generated by a complex weight function with integrationtaken along a path in the complex plane.The authors following R.D.Morton and A.M.Krall [10] research work are discussing the orthogonality from the point of view of distribu-tion theory.In doing so a third and new kind of orthogonality is pointed out.In some of the authors' forthcoming papers vrious kinds of orthogonality for polynomialsin several variables will be discussed [14]—[16],while the appropriate papers will deal withC.Brezinski's comprehensive very recent results [17] and with M.Picone's“total derivativeoperators”systems in the framework of D.Mangeron's polyvibrating or polywave equations,respectively.
