HP calculators, slide rules, and Forth all have something in common: reverse polish notation or RPN. Admittedly, slide rules don’t really have RPN, but you work problems on them the same way … ...

I admit it, I “cut my teeth” on HP calculators in the 1970s, but complex infix notation with parentheses only became easy to use once 5×7 dot matrix alphanumeric displays became available ...

Reverse Polish Notation was first suggested by three American mathematicians Arthur Burks, Don Warren and Jesse Wright in 1954, but was not fully elucidated until 1957 when Charles Hamblin, an ...