[zelphirkalt]

Notationwise this is not so great. Yet another special syntax, the subscript, is used for expressing an operation. And subscript is already used for multiple purposes, even with my limited math knowledge: base of logarithm and labels for selecting a part of something bigger, like a matrix.

Notationwise it would be good to do as some computer languages do and just use a name and wrap everything: (+ (* (^ (_ something D) C) B) A) = imagine this one graphically: ((((something_D)^C) * B) + A). No ambiguity, no question in what order to apply operations.