+// If include_fixed_spacing is true, the manually fixed spacings
+// induced by stretchable=0 or alignment-distances are included
+// in the minimum translations here. If you want to find the minimum
+// height of a system, include_fixed_spacing should be true. If you
+// want to actually lay out the page, then it should be false (or
+// else centered dynamics will break when there is a fixed alignment).