a) Lights flash and colours change.
b) The above occurs.
c) If I noticed it, it occurred. If I didn’t notice it, it still could have occurred.
d) If anybody noticed it, it certainly occurred.
e) If no one noticed it, it could have occurred.
f) If everyone noticed it, it definitely occurred.
f.2) If one person did not notice it, could the occurrence be in doubt?
g) Then what occurs that absolutely everyone notices?