By default, a general fact will refer to a general, descriptive, and non-tautological fact, associated with a possibly multivariate variable *X*: *Ω* -> M(*X*). It is a statement that is true for any element of *Ω*. A general fact is a negative (or restrictive) statement about at least one descriptive value of M(*X*): there exists a non-empty subset *α* of M(*X*) such that no being of *Ω* takes a value in *α*.

Remark: if the set *Ω* is unknown, the statement “there exists a non-empty subset of M(*X*) such that no element of *Ω* takes a value in it” should not be called a fact but a conjecture.