The main goal of the article is to reveal the role of mutual recognition principle in the realization of freedom to provide services and to appraise the effectiveness of its application. The author stresses the polysemantic feature of analyzed principle in the light of different doctrinal approaches to its substance. On the basis of the analysis of secondary EU law, EU case-law and diverse doctrinal views the author defines the content of mutual recognition principle. The article contains a comparative analysis of goods and services as objects of cross-border economic relations and on the basis of this research the author determines peculiarities of the application of mutual recognition principle in services sector. The study examines the application of mutual recognition principle and the author formulates factors restricting its realization. A particular attention is paid to the analysis of EU legislation concerning the recognition of professional qualifications.
Finite state transducers over semigroups can be regarded as a formal model of sequential reactive programs. In this paper we introduce a uniform tech- nique for checking eectively functionality, k-valuedness, equivalence and inclusion for this model of computation in the case when a semigroup these transducers op- erate over is embeddable in a decidable group.