  One of the so-called viable modified gravities is analyzed. This kind of
gravity theories are characterized by a well behavior at local scales, where
General Relativity is recovered, while the modified terms become important at
the cosmological level, where the late-time accelerating era is reproduced, and
even the inflationary phase. In the present work, the future cosmological
evolution for one of these models is studied. A transition to the phantom phase
is observed. Furthermore, the scalar-tensor equivalence of f(R) gravity is also
considered, which provides important information concerning this kind of
models.
