Abstract-The calculation of variables of one metering type by the variables of others metering types as the process leads to the forms of logic which are described by means of the collineation group of the projective geometry. Missing metering types are replaced with the appropriate logic principles. The logic of sufficiency (preferences) on the basis of orders and the logic principle of duality is considered in detail on an RNA connectivity analysis example. The minimal sum of diagonal elements in the cross-tabulation of two finitely-linear combinations (symptoms) of fragments which differ by a shift on the given quantity of symbols is chosen as a relation between two dichotomizing series. If this relation is zero then correct classification takes place. In this paper the probability of random classification with given number of errors is estimated. Logic principle of duality allows to distinguish between weak and strong statistically significant relations.