User blog comment:Alejandro Magno/Extension of the Alphabet Hierarchy/@comment-5029411-20141006150934

a&<1(2)2>[A](x) = a&<1,1,1,...,1,1,2>[A](x) with x 1's

a&<1(2)3>[A](x) = a&<1,1,1,...,1,1,2(2)2>[A](x) with x 1's

a&<1(2)1(2)2>[A](x) = a&<1(1)1,1,1,...,1,1,2>[A](x) with x 1's

a&<1(3)2>[A](x) = a&<1(1)1(1)1(1)...(1)1(1)1(1)2>[A](x) with x 1's

a&<1(1,2)2>[A](x) = a&<1(&<1(&<1(...)2>[A])2>[A])2>[A][A](x) with x nested