  We argue that a Standard Model decoupling limit is generically the necessary
ingredient which makes scenarios of electro-weak symmetry breaking viable. This
applies especially also to models of dynamical electro-weak symmetry breaking.
Additional requirements are only that the mass predictions of a given model
(e.g. predictions or theoretical limits on the Higgs or top mass) are
consistent with existing data. We discuss the necessary ingredients for
dynamical symmetry breaking and present a dynamically broken
left-right-symmetric model as an example. The model exhibits such a decoupling
limit, is phenomenologically viable and leads to interesting mass predictions
and relations which are further examined.
