Lisp does NOT use RPN - Re: cctalk Digest, Vol 125, Issue 13

On Jan 9, 2014, at 11:59 AM, Ian King <IanK at LivingComputerMuseum.org> wrote: Jan ?ukasiewicz originally came up with prefix notation. Since he was a Polish mathematician and non-Poles are likely to have trouble with ??ukasiewicz? it became known as ?Polish notation?. At a later time, a variant was invented where the operator is at the end, which works great with stack machines and as a way to do infix expression parsing. That?s the reverse of conventional ?ukasiewicz notation so it became ?Reverse Polish Notation? (or sometimes ?Polish Postfix Notation?). Both have the property that you don?t need parentheses; execution order is evident by the placement of the operators. Mapping between classic and reverse forms is trivial, simply move the operator from one end to the other. Forth is postfix notation, because the Forth execution model is a stack machine with the Forth ?words? corresponding directly to the execution of primitive operations that act on the stack. Forth is really an assembly language rather than a high level language; those familiar with Burroughs mainframe machines will see the analogy with the machine language of those systems. paul