Please help me. I'm new in Haskell programming, but wrote some things in Scheme. I make so function: fib 1 = 1 fib 2 = 2 fib n = fib (n-1) + fib (n-2) And when I call "fib 30" it works about 5 seconds. As for me it's really TOO SLOW. Tell me please if I have something missed, maybe some compiler (interpretaitor) options (I use ghc 6.6.1). P.S. As I understand function "fib n" should be calculated one time. For example if I call "fib 30" compiler builds tree in which call function "fib 28" 2 times and so on. But as for lazy calculation principle it should be calculated just ones and then it's value is used for all other calls of this function with the same argument. But it seems that this principle doesn't work in this algorithm. -- View this message in context: http://www.nabble.com/Fibbonachi-numbers-algorithm-work-TOO-slow.-tf4752338.... Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.