An ambitious logic-based system might use logical expressions of the facts. Less ambitiously, programmers would use them in designing data mining systems. People persist in time. People want objects. People consume objects and want more.
Some objects are permanent on the relevant time scale.
There are kinds of people and kinds of objects. People have attributes, and these attributes change, although some are permanent. People buy objects with money. This uses up money and people do not buy at a rate much higher than they get more money. We suppose these are spelled out in some literature.