Each primitive domain carries its own internal structure. Individuals are unique atomic entities in the model which correspond to real objects in the world. Times are individuals of distinguished type, representing temporal locations and, similar to times, places are individuals which represent spatial locations.
Various relations hold or fail to hold between objects.
A relation has argument roles which must be occupied by appropriate objects. They are used to refer to arbitrary objects of a given type. A parametric infon is the basic computational unit. If a situation s supports an infon , this is denoted by s . Otherwise, it is written as s .