Some definitions of interest.
world	Def World Def == T:IdIdType Def == TA:IdIdType Def == M:IdLnkIdType Def == (i:Id(x:IdT(i,x)))(i:Idaction(w-action-dec(TA;M;i))) Def == (i:Id({m:Msg(M)| source(mlnk(m)) = i } List))Top
	Thm* World  Type{i'}
IdLnk	Def IdLnk == IdId
	Thm* IdLnk  Type
Id	Def Id == Atom
	Thm* Id  Type
w-M	Def w.M == 1of(2of(2of(w)))

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