Temporal difference between observations, zoom. This figure is the same as above, but focused on the solution, with the crosshatched region showing the constraints on the period above and beyond the limit bars. Here, one can see an example of a branch in the possibilities at Δ₁, as two possible periods from Δ₂ fall within the period range described by Δ₁. This is a relatively common occurrence, so the code has been designed to follow all possibilities should a branching occur.