A fundamental point due to its repercussions throughout the document is the discussion of some theoretical references, that is, to establish the theoretical status of the nominal elements of the structure, their character of notion, the poverty of its definition, its empirical nature or its belonging, as a category, to a theoretical body, that is, to establish the theoretical status of the nominal elements of the structure, its character as a notion, the poverty of its definition , its empirical nature or its belonging, as a category, to a theoretical body.