exactly what "everybody knows", frequently with regards to a certain neighborhood; something which cannot sensibly be contested.
A special style of understanding for a small grouping of agents, in a way that when all representatives in friends G understand p, they all know that they understand p, each of them know that all of them know that they know p, and so on ad infinitum.
everything typically recognized to everyone
What "everybody knows", frequently with reference to a particular community; something that cannot fairly be contested.
a particular types of knowledge for a team of agents, so that whenever all of the representatives in a group G understand p, they all know that they know p, each of them know that they all understand that they know p, and so forth ad infinitum.