The namespace for an MxModel includes all of the non–independent models in a hierarchical tree. Thus, for instance, parameters can be constrained between two submodels as shown in Figure 4. Constraints cannot be made to elements in an independent submodel — one of the conditions that allows independent estimation of branches of a model tree that have been marked as independent. In Figure 4 four elements from three matrices across two submodels have all been constrained to be equal by labeling the corresponding elements as “d”.
