noun
reverse Polish notation; RPN
A mathematical notation in which operators follow their operands, used in computing and some calculators.
逆ポーランド記法では、3と4を足す式は「3 4 +」と書く。
In reverse Polish notation, the expression for adding 3 and 4 is written as '3 4 +'.
Polish notation places operators before operands (prefix), while reverse Polish notation places them after (postfix).
From 逆 (reverse) + ポーランド (Poland) + 記法 (notation), a calque of English 'reverse Polish notation', named after Polish logician Jan Łukasiewicz.