User blog comment:Syst3ms/Funky Notation/@comment-35470197-20181003080925/@comment-35470197-20181004132857

But when we consider \(11\), then a problem occurs.

First, the main array is \([1]\), and \(b\) is its unique entry \([1]\), Since \([1] \neq 0,[0]\) is a nested array of \(1\), we go to the step 3 in Process. Then \(A_1\) becomes the nested array \([1]\), and \(b\) becomes its first entry \(1\).

Next, \(b = 1\) is a nested array with respect to \(A_1 = [1]\) but is not a nested array with respect to \(A_0 = 1\). Therefore the abbreviation of "in what array a nested array is" causes ambiguity.