bilateral implication equivalence, implication bilateral opposition opposition bilingualism [Lat. ‘two’, ‘tongue, language’]

The property of descriptive terms which are predicated upon the opposition of two units, e.g. upon the presence or absence of certain features. ( also binary opposition, distinctive feature)

Classificatory and descriptive method used in many disciplines (e.g. biology, information theory, logic, mathematics) which is based on two values. A basic principle of this system is the fact that essentially all-even the most complex-states of affairs and occurrences can be reduced to a finite set of elementary yes/no-decisions: for example, the 64 squares of a chess board can be determined by six yes/no-questions, since 26=64. Binary opposition goes back to classical logical principles and can be interpreted as a function in propositional logic in the sense of ‘X is true or is not true’ ( formal logic). Primarily, binary decisions can be simulated in practice with simple technical devices, such as by an electrical switch with on/off positions or by punch cards with hole/ non-hole markings. It is on this principle that the analytical workings of a calculator are based. In linguistics, especially in phonology, Jakobson and Halle (1956) introduced the method of binary segmentation by proposing a universal inventory of twelve binary phonetic features to describe all languages in the world ( distinctive feature). Moreover, the concept of binary opposition has been adapted to morphology,

though some doubts remain as to the general validity of the process of binary segmentation for natural languages (see Henrici 1975). ( markedness)

References

Halle, M. 1957. In defense of number two. In E. Pulgram (ed.), Studies presented to J.Whatmough. The Hague. 65-72.