  Iterations of odd piecewise continuous maps with two discontinuities, i.e.,
symmetric discontinuous bimodal maps, are studied. Symbolic dynamics is
introduced. The tools of kneading theory are used to study the homology of the
discrete dynamical systems generated by the iterations of that type of maps.
When there is a Markov matrix, the spectral radius of this matrix is the
inverse of the least root of the kneading determinant.
