  We have proposed a method in the context of BFFT approach that leads to
truncation of the infinite series regarded to constraints in the extended phase
space, as well as other physical quantities (such as Hamiltonian). This has
been done for cases where the matrix of Poisson brackets among the constraints
is symplectic or constant. The method is applied to Proca model, single self
dual chiral bosons and chiral Schwinger models as examples.
