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C00002 00002	.require "memo.pub[let,jmc]" source
C00003 ENDMK
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.require "memo.pub[let,jmc]" source
.cb JOINT KNOWLEDGE

	The object of this note is to distinguish joint knowledge
of a set of people from knowledge that they all have.  When an
event, such as a loud noise, occurs in the presence of several
people, they all know it.  Moreover, each of them will be aware
that the others know it.  There is controversy concerning how far
this goes.

	Suppose we use %2S*p%1 as a notation for %2person S knows
proposition p%1.  We then can write %2S1*S2*p%1 for %2S1 knows
that S2 knows p%1.  One controversy is whether it is reasonable
to assert that %2(S1*S2*)%51000%2p%1