In this paper we study the necessary and sufficient conditions for the training of conditional relations, the formation of equivalence classes and relations of "equivalence - equivalence". It further investigates the influence of the training structure in the formation of relations of "equivalence-equivalence" and the possible correlation between the baseline relations and the formation of derived relations and response manner under conditions of competition between "equivalence - equivalence "and relations with physical similarity. The results showed that when forming only two equivalence classes of three members, it is possible to establish relations of "equivalence-equivalence". However, in these conditions, the training structure does not affect the performance testing of derived relations. Also, if two modes of response, by "equivalence-equivalence" and physical similarity are available from the beginning of test, mode of responding to the derived relationships prevailed over the physical similarity of stimuli.