If ~1050 people were laid off from January 1 through September 30, 520 in one event is a pretty big number (not saying it's wrong, I have no direct knowledge of what is or might be coming).
From Xerox' Q3 2018 SEC filing:
Worldwide Employment
Worldwide employment was approximately 33,200 as of September 30, 2018 and decreased by approximately 2,100 from December 31, 2017, largely driven by our business transformation. Approximately half of the reduction was associated with restructuring actions, while the remainder resulted from net attrition (attrition net of gross hires), of which a large portion is not expected to be backfilled.