nsider the funciton values to be [\delta * n_low, \delta* (n_low+1), \cdots, \delta * n_high] for a stored delta </span>
<span class="sd">    - If an edge crosses a value, it has a vertex (so that the inverse image of any integer is only vertices, not interiors of edges)</span>
<span class="sd">    - An internal delta is stored so that this can be interpreted as function values [\delta * n_low, \delta* (n_low+1), \cdots, \delta * n_high] </span>
<span class="sd">    &quot;&quot;&quot;</span>

<div class="vi