As a special case, if we want to represent an object without giving any properties, we can attach an empty specification list to the object name, e.g.
thing[].
In this example a class thing is "created" that does not have any properties (yet).
If we use a similar expression that consists solely of an object name (without the empty pair of brackets, i.e. thing.), it is treated as a 0-ary predicate symbol (see the section below).