message: add missing elements in plookup example
diff: @@ -276,7 +276,7 @@ $$
  t_0[i] + j t_1[i] + j^2 t_2[i] = t_0[l] + j t_1[l] + j^2 t_2[l]
  $$
  -For example, if $f = \{1, 2, 2, 3\}$ and $t = \{2, 1, 2, 3\}$, then $\text{sorted}(f, t) = \{2, 2, 1, 1, 2, 3\}$ would be one way of sorting things out. But $\text{sorted}(f, t) = \{2, 2, 2, 1, 1, 3\}$ would be incorrect.
  +For example, if $f = \{1, 2, 2, 3\}$ and $t = \{2, 1, 2, 3\}$, then $\text{sorted}(f, t) = \{2, 2, 2, 1, 1, 2, 3, 3\}$ would be one way of sorting things out. But $\text{sorted}(f, t) = \{ 2, 2, 2, 2, 1, 1, 3, 3 \}$ would be incorrect.
  ## Recap
  