  Analogously, if there is a later event satisfying (2)–(5), but no earlier event, we have a conjunctive fork open to the past  (Figure 6(b)).  If an earlier event C and a later event D both satisfy (2)–(5), then ACBD forms a closed fork  (Figure 6(c)).  Reichenbach claimed that in our world, there are a great many forks open to the future, but few or none open to the past. Moreover, he proposed that the direction from cause to effect could be grounded in this statistical asymmetry.