So the app adds them in the background.
You understand that apps can do things that you don’t see, right??
...
You are functionally illiterate.
RPN is not an "app." RPN is a NOTATION. That's what the N is. It is a completely different way of doing math! It works on paper! You troll! It is a syntax for performing calculations using a stack-based method. There are no fucking parentheses - anywhere. It has no need for that concept. Operations use the top values on the stack. Order of operations is implicit in the order of operands, and completely different from the one thing you insist is both universal, and mutable, and a notation, and the rules, and whatever else lets you never shut the fuck up.
Do you know anything that's not in a textbook for children?