  We present a multi-modal action logic with first-order modalities, which
contain terms which can be unified with the terms inside the subsequent
formulas and which can be quantified. This makes it possible to handle
simultaneously time and states. We discuss applications of this language to
action theory where it is possible to express many temporal aspects of actions,
as for example, beginning, end, time points, delayed preconditions and results,
duration and many others. We present tableaux rules for a decidable fragment of
this logic.
