13. The system of claim 12 , wherein the error checker is further configured to store the error checking result in a second queue.
13. The system of claim 12 , wherein the error checker is further configured to store the error checking result in a second queue. 14. The system of claim 13 , wherein the computer program logic further comprises an error indicator configured to be executed by the first thread of execution, the error indicator being further configured to retrieve one or more error checking results from the second queue and, for each retrieved error checking result: determine whether an element currently exists within the document that has an ID that is the same as the ID associated with the retrieved error checking result, and in response to the determining that the element currently exists within the document that has the ID that is the same as the ID associated with retrieved error checking result, generate an indication that the element is m error.