  Action models are semantic structures similar to Kripke models that represent
a change in knowledge in an epistemic setting. Whereas the language of action
model logic embeds the semantic structure of an action model directly within
the language, this paper introduces a language that represents action models
using syntactic operators inspired by relational actions. This language admits
an intuitive description of the action models it represents, and we show in
several settings that it is sufficient to represent any action model up to a
given modal depth and to represent the results of action model synthesis, and
give a sound and complete axiomatisation in some of these settings.
