  The self-consistent equations for the order parameters of Bose-Einstein
condensation (BEC) of molecules and Bardeen-Cooper-Schrieffer (BCS)
condensation of atoms in a Fermi gas of atoms with an attractive two-body
interaction between atoms have been derived within the Hartree-Fock-Bogoliubov
approximation from the path integral representation of the grand partition
function. We have found that the order parameters for BEC and BCS are
proportional to each other, which implies that BEC and BCS onsets
simultaneously. We have also found that the common critical temperature of BEC
and BCS increases as the average number of molecules increases and that the
atom-molecule coupling enhances the common critical temperature.
