module Main where {

newtype Rec a b = Rec {deRec :: Rec a b -> a};

infixl 1 >|>;
infixl 1 <|<;
(>|>) = Rec;
(<|<) (Rec x) = x;

fix f = (\x -> f (x <|< x)) (Rec (\x -> f (x <|< x)));

factorial = fix (\f x -> if x<=1 then 1 else x*f(x-1));

main = do {
   x <- getLine;
   putStrLn (show (factorial (read x)))
   }

}

GHC crashes with this error:

[1 of 1] Compiling Main             ( /Users/iOne/Documents/Test.hs, /Users/iOne/Documents/Test.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 7.6.3 for x86_64-apple-darwin):
	Simplifier ticks exhausted
    When trying UnfoldingDone a_sMx{v} [lid]
    To increase the limit, use -fsimpl-tick-factor=N (default 100)
    If you need to do this, let GHC HQ know, and what factor you needed
    To see detailed counts use -ddump-simpl-stats
    Total ticks: 7121

(This works fine in GHCi).