Classification of all Δ-coherent pairs

18 pages, no figures.-- MSC1991 codes: 42C05, 33C25.MR#: MR1785535 (2001d:42016)Zbl#: Zbl 0972.42017In a recent work we have proved that if $(u_0,u_1)$ is a δ-coherent pair of linear functionals, then at least one of them must be a classical discrete linear functional under certain conditions. In this paper we present a similar result for $D_\omega$-coherent pairs and the description of all δ-coherent pairs. Furthermore, by using a limit process we recover the classification of all coherent pairs of positive definite linear functionals.The work of L.A. and E.G. has been partially supported by Xunta de Galicia-Universidade de Vigo under grant 645021703. E.G. also wishes to acknowledge partial financial support by Dirección General de Enseñanza Superior (DGES) of Spain under Grant PB-96-0952. The research of F.M. was partially supported by DGES of Spain under Grant PB96-0120-C03-01 and INTAS Project 93-0219 Ext.Publicad