On a local form of Lobachevski's functional equation
Basic concepts concerning binary and ternary relations are extended to relations of arbitrary arities and then investigated.
A binary relation language is an important tool of the theory of measurements (see, for example, book [5]). Specifically, the theory of nominal and ordinal scales is based on theories of equivalent relations and weak orderings. These binary relations have a simple structure which can be described as follows (bearing in mind a context of the measurement theory).