Decoupling of holes in the tJ model at J=2t from spl(2,1) symmetry

The binding energy of two p=0 holes in the tJ model on a square lattice is shown to vanish at J=2t due to the spl(2,1) symmetry at this point. in any background of antiferromagnetic type, with finite total spin in an infinite volume, the binding energy at x=0 hole doping vanishes at least as (J−2t)s2 as J→2t. These exact results may serve as tests of more comprehensive calculations of interactions of holes in the tJ model