# reverse polish notation (RPN)

Reverse Polish Notation (UPN), Reverse Polish Notation (RPN), is a notation for programmatic arithmetic operations. It is named after the Polish mathematician Lukasiewicz and deals with the linkage ofoperand and operator

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In reverse Polish, the operand is entered first, followed by the operator. Example (a+b)*(a-b) is written in UPN: ab+ ab- *. UPN notation makes arithmetic operations more transparent, and also saves manipulation in more complex arithmetic operations. The intermediate results must be stored in stack memories. The reverse Polish notation is used in the Forth programming language, among others.