This thread follows on from : https://www.physicsforums.com/threa...ot-worthy-of-maths-forum.880724/#post-5534559 . Anybody ever used Polish notation or reverse Polish notation for computational formulae ? Use of either is supposed to eliminate ambiguity and make the flow of computations logical . I only ask out of curiosity . The very expensive HP programmable calculator we had at Mtu during the late 1970's had reverse Polish notation input . That is the only real world use I have ever come across .