Comment on Hydrogen-Antihydrogen collisions
  A comment on a recent paper by P. Froelich et. al., Phys. Rev. Lett., 84, 4577 (2000) on hydrogen-antihydrogen collisions and on matter-antimatter reactions in general. The center of mass of a stable HHbar system has prochiral character. It is not necessary to look for large scale anti-matter domains at distances Mpc away or at the cosmological horizon. 
G. Van Hooydonk (U Ghent)