Specifying a Definition. Explanations Comments, Examples 1a. A system is a set of mutually dependent variables. Non-systems are easier to describe than systems.
Systems take much more specification.
To say that a set of variables comprises a system is to hypothesize that each variable in the set is a function of every variable in the set. It is circular unless one realizes that it is meant to be used in a self-correcting inquiry process. In practice, sets of variables are said to be more or less systemically related. Variables are sets whose elements are called values. Dependency is a relationship among variables.