User blog comment:Wythagoras/FGH of Array Notations/@comment-5029411-20130707162841/@comment-5029411-20130707210236

lambda(1,-1) = 0 and lambda(1,n+1) = theta(Omega_Omega...Omega_Omega_{lambda(1,n)+1})

Then lambda(2,0) = lambda(1,lambda(1,...(lambda(1,lambda(1,0))...)).

Let lambda(*) = theta(*)|(0), then theta(Omega_*) = theta(0,*)|(0).