  We give some semantic results for an epistemic logic incorporating dynamic
operators to describe information changing events. Such events include
epistemic changes, where agents become more informed about the non-changing
state of the world, and ontic changes, wherein the world changes. The events
are executed in information states that are modeled as pointed Kripke models.
Our contribution consists of three semantic results. (i) Given two information
states, there is an event transforming one into the other. The linguistic
correspondent to this is that every consistent formula can be made true in
every information state by the execution of an event. (ii) A more technical
result is that: every event corresponds to an event in which the postconditions
formalizing ontic change are assignments to `true' and `false' only (instead of
assignments to arbitrary formulas in the logical language). `Corresponds' means
that execution of either event in a given information state results in
bisimilar information states. (iii) The third, also technical, result is that
every event corresponds to a sequence of events wherein all postconditions are
assignments of a single atom only (instead of simultaneous assignments of more
than one atom).
