  When Technicolor (TC), QCD, Extended Technicolor (ETC) and other interactions
become coupled through their different Schwinger-Dyson equations, the solution
of these equations are modified in comparison with the ones of the isolated
equations. The change in the self-energies is similar to the one obtained in
the presence of four-fermion interactions, but without their \textsl{ad hoc}
inclusion in the theory. In this case TC and QCD self-energies decrease
logarithmically with the momenta, what allow us to build models where ETC boson
masses can be pushed to very high energies, and their effects will barely
appear at present energies. Here we present a detailed discussion of this class
of TC models. We first review the Schwinger-Dyson TC and QCD coupled equations,
explaining the origin of the asymptotic self-energies. We develop the basic
ideas of how viable TC models may be built along this line, where ordinary
lepton masses appear naturally lighter than quark masses. One specific unified
TC model associated with a necessary horizontal (or family) symmetry is
described. The values of scalar and pseudo-Goldstone boson masses in this class
of models are also discussed, as well as the value of the trilinear scalar
coupling, and the consistency of the models with the experimental constraints.
