Common truth ≠ uncertain information in public

what is Common truth ?

   ⑴ if picture A exist 
   ⑵ picture A shows event A exist
   ⑶ if picture A = true => event A = true

uncertain information in public

pattern 1⃣

   ⑴ if picture E not exist 
   ⑵ player E watches event E happens
   ⑶ if player E says event E = true => event E = true

pattern 2⃣

   ⑴ player E watches event E happens
   ⑵ player G take photo of other event G
   ⑶ if picture of event E not exist, 
       event G have more probability than event E
   (2 event E G may exist at the same time)

point:

   ⑴ when there are 2 possible past world A & C, remaining public information certificate more possible world
   ⑵ if good event happens, lets remain photo

common truth, more stable to remain in public, when info overwritten ( by attack, or accident ).

   when info overwritten
   1 time paradox
   2 when 2 world string merges
   3 when graviton overwritten