Pencil sketch by Laura Nagle

I have a calculator with no
Equal key
That key did not fall off
That key was never there

I drive a Hewlett Packard
An HP 50g
It runs RPN
Reverse Polish Notation

My calculator needs neither
Equal, nor
Parenthesis keys
It is post fix and has an
Essentially unlimited stack

Its abilities are also
Essentially unlimited
Although I use few of them,
The ones that I do use
Are important
The method is superb

I have major arguments of
Philosophical sort
With algebraic calculators
My Hewpie does not fight me,
We live in peace