 It is worth emphasizing that for the purposes of our formalization of this scenario, these two are the only propositions of interest. We are restricting our attention to \(\textit{Atom}=\{p,q\}\). In early presentations of epistemic logic and in much of standard epistemic logic at present, all the atoms of interest are included from the outset. Obviously, this is an idealized scenario. It is important to notice what this approach leaves out. Considerations that are not captured in this way include the appearance of novel atoms; the idea that other atomic propositions might be introduced at some future state via some process of learning for example, or the question of an agent’s awareness of propositions; the scenario in which an agent might be temporarily unaware of some atom due to some psychological or other factor (see  Section 4  for references to so-called awareness logic). For now, the main point is that standard epistemic logic begins with the assumption that the set Atom exhausts the space of propositions for the agent.