Version Logic

Routine as a mode of inference (working conduction) engages version (-vert) as trace.  The stakes and opportunities of version (the directionality of attitude), the potentiality of turning in relation to problem on the plane of immanence, may be appreciated relative to the historical developments in the several practices and disciplines that exploit this register.  One example is the inference procedures systematized by categorical propositions.  Any textbook of logic covers the manipulations of the logical square (Aristotle), including conversion, obversion, and contraposition.

The converse of any categorical proposition is the new categorical proposition that results from putting the predicate term of the original proposition in the subject place of the new proposition and the subject term of the original in the predicate place of the new. Thus, for example, the converse of "No dogs are felines" is "No felines are dogs," and the converse of "Some snakes are poisonous animals" is "Some poisonous animals are snakes."

In order to form the obverse of a categorical proposition, we replace the predicate term of the proposition with its complement and reverse the quality of the proposition, either from affirmative to negative or from negative to affirmative. Thus, for example, the obverse of "All ants are insects" is "No ants are non-insects"

The contrapositive of any categorical proposition is the new categorical proposition that results from putting the complement of the predicate term of the original proposition in the subject place of the new proposition and the complement of the subject term of the original in the predicate place of the new. Thus, for example, the contrapositive of "All crows are birds" is "All non-birds are non-crows,"

 [Interactive Demo]