1. A method comprising: receiving, by one or more processors, a pending update list including a first plurality of items, wherein each item of the first plurality of items describes an update to a hierarchically structured document; adding, by one or more processors, each of one or more items of the first plurality of items to a subsumed update list having a second plurality of items, wherein the subsumed update list is ordered based, at least in part, on a document order and on a target node of each of the second plurality of items; applying, by one or more processors, subsume logic to each of the one or more items based, at least in part, on the second plurality of items, wherein applying the subsume logic to each of the one or more items pre-processes the pending update list, thereby consolidating redundant updates and removing conflicting updates; comparing, by one or more processors, a first target node of a first item of the one or more items to a second target node of a second item of the second plurality of items, wherein the second item is a tail of the subsumed update list; responsive to determining, by one or more processors, that the first target node is the same as or is a descendant of the second target node, applying, by one or more processors, the subsume logic to the first item based, at least in part, on at least one subsume matrix; and responsive to determining, by one or more processors, that the subsume logic has been applied to each item of the first plurality of items, executing, by one or more processors, each of the second plurality of items of the subsumed update list.