 &lt; &gt; = &lt;= &gt;=
The syntax for referring to a fluent value is to use the fluent
property name and as argument a variable formed from the name of the
object sort to which this fluent refers. When a complete expression is
added to the list of expressions the syntax will be checked.
<h4>Events</h4>
<b>Events</b> are transitions that are brought about by the change in
numeric properties and are not directly invoked by the planner. To
create an <b>Event</b> a normal state transition is created and on th