 In order to solve the measurement problem Everett proposed dropping the collapse dynamics (rule 4b) from the standard collapse theory and taking the resulting physical theory to provide a complete and accurate description of all physical systems in the context of all possible physical interactions. Everett called the theory pure wave mechanics. He believed that he could deduce the standard statistical predictions of quantum mechanics (the predictions that depend on rule 4b in the standard collapse formulation of quantum mechanics) in terms of the subjective experiences of observers who are themselves treated as ordinary physical systems within pure wave mechanics. 