Integrity constraints (ICs) play a key role in the definition of conceptual schemas. In the UML, ICs are usually specified as invariants written in the OCL language. However, due to the high expressiveness of the OCL, the designer has different syntactic alternatives to express each IC. In the context of the MDA, the choice of a particular definition has a direct effect on the efficiency of the automatically generated implementation. The method presented in this paper assists the designer during the definition of ICs by means of generating equivalent alternatives for the initially defined constraints. Our method can also be applied to help in the detection of equivalent (redundant) constraints and as a tool to facilitate the learning of the OCL.