AUTOMORPHISM PROPERTIES OF STATIONARY-LOGIC

By means of an Ehrenfeucht-Mostowski construction we obtain an automorphism theorem for a syntactically characterized class of L(aa)-theories comprising in particular the finitely determinate ones. Examples of L(aa)-theories with only rigid models show this result to be optimal with respect to a classification in terms of prenex quantifier type: Rigidity is seen to hinge on quantification of type ...FOR-ALL...stat... permitting of the parametrization of families of disjoint stationary systems by the elements of the universe.