Polish Notation

I would like to see support for prefix notation variants of arithmetic expressions, which is easier to reason about for a computer, and eliminates the need for parenthesis. If the first argument is an operator, the arithmetic parsing algorithm should switch over to prefix-mode.

$ * + 1 3 5
20
$ > 1 3
0 (return exit status 1)
$ < 1 3
1 (return exit status 0)