  This paper shows the existence of a periodic orbit with singularity in the
symmetric collinear four body problem. In each period of the orbit, there is a
binary collision (BC) between the inner two bodies and a simultaneous binary
collision (SBC) of the two clusters on both sides of the origin. The system is
regularized and the existence is proven by using the implicit function theorem
and a continuity argument on differential equations of the regularized
Hamiltonian.
