You cannot have an expression at the top-level. Haskell program entry point is a main function in Main module. Also print fib 5 calls print with two arguments, you need to do:
main = print $ fib 5
or
main = print (fib 5)
You cannot have an expression at the top-level. Haskell program entry point is a main function in Main module. Also print fib 5 calls print with two arguments, you need to do:
main = print $ fib 5
or
main = print (fib 5)