Moduli spaces of model real submanifolds: two alternative approaches

Instead of the invariant theory approach employed by Beloshaoka and Mamai for constructing the moduli spaces of Beloshapka's universal CR-models, we consider two alternative approaches borrowed from the theories of equivalence problem and Lie symmetries, each of them having its own advantages. Also the moduli space M(1,4) associated to the class of universal CR-models of CR-dimension 1 and codimension 4 is computed by means of the presented methods.