Illustrations For Discussion

Scenario 1

 15                                                       15
  |       add 67                                           |
  23     ----->     23 <====New Concept --->  68 -------> 23
 / \               / | \                     / | \        / \
45 46            45 46 67                  45 46 67      45 46

Scenario 2

 15                                                       15
  |       add 67                                           |
  23     ----->     23 <====New Concept --->  68 -------> 23
 / \               / | \                     / | \        / \
45 46            67 45 46                  67 45 80----->46 45
                      / \                        / \
                     70 71                     70 71

Scenario 3

A              add syn
3 <-- 1 --> 2 -------->  4 <-> 2 <==== New Concept --> 4 <-> 5 this is unclear…. Either:

A                        B
3 <-- 1 --> 2      &     2 -> 4     this is ok but implies B existed before A

A's view                 B's view
3 <-- 1 --> 2      &     4 -> 2   this is ok and doesn’t change the definition of 2