Some definitions of interest.
w-action	Def Action(i) == action(w-action-dec(w.TA;w.M;i))
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'}
Id	Def Id == Atom
	Thm* Id  Type
nat	Def  == {i:| 0i }
	Thm*   Type
w-a	Def a(i;t) == 1of(2of(2of(2of(2of(w)))))(i,t)

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