User blog comment:Wythagoras/Dollar function: final version/@comment-5029411-20131116182007

Subscript-Array Notation (And Extended One.)

[<0>...<0>n] = [<0>...< <0>...<0>n-1> [0]]

[<0>...<0>0] = [0]

a = a-1<[0]>...<[0]> (b <[0]>'s)