TITLE: What is this type of math notation called? (+ 4 5)
QUESTION [14 upvotes]: So I've been looking for a general name of this type of mathematics notation (google hasn't been very useful) so that I can learn more about it. Basically, the symbols are in the form of functions and the numbers are the inputs to the function.  + is the function taking 4 and 5, outputting 9 so, (+4 5) = 9. Formulaic  (* a b ) = a * b.  Where ' * ' can be any basic math symbol.  More complicated forms are: (+ 4 (+ 5 1)) = 4 + (5+1) = 10. 4 being input for 'a' and (5+1) being 'b' in (* a b ).
Hope it makes sense.

REPLY [42 votes]: It is normal Polish notation or prefix notation.