A rule describes the property of a facility as a boolean argument at each point of time. An operational rule is valid for one point of time, if the specified logical element is valid for the data point at this moment. Properties of buildings are predominantly defined as physical parameters such as temperature, pressure or volumetric flow rate. Also operational characteristics of facilities can be defined by operational rules as properties for operational states. These could be control notifications from the building automation (for example on/off

[-], valve positions [%] or readings from counters such as hours of operation) or KPIs.

A comment can be added to an operational rule by /* comment */. The rule cannot begin with a comment nor only consist of the comment itself.

Example for an operational rule:

`I1 < 20`

with I1 = ambient temperature