Changes

'''Zero''' (written "0") is the additive identity of the real numbers.  One is the successor of zero.   

'''Zero''' (written <math>0</math>) is the additive identity of the real numbers.  One is the successor of zero.   

In the BC/AD timeline, the year zero is omitted.  History proceeds from December 31, 1 BC to January 1, 1 AD.  This can lead to counting errors when summing up spans of time that cross the transition point, because people often assume the timeline is constructed like the set of integers.

In the BC/AD timeline, the year zero is omitted.  History proceeds from December 31, 1 BC to January 1, 1 AD.  This can lead to counting errors when summing up spans of time that cross the transition point, because people often assume the timeline is constructed like the set of integers.