PPT Slide
You see that in every state tx the imaginary state (s2 Øj) is accessible via x+2 steps. Sending confirmations does not lead to common knowledge
in the model t consisting of all states txÎN
To formally prove that common knowledge can’t be
increased in t I will make use of the fact that:
that every run through t is non-simultaneous and
that common knowledge is constant in non- simultaneous runs.