[commit: base] type-nats: Fix the type of IsEven (727d63c)

[Iavor Diatchki]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

On branch  : type-nats

http://hackage.haskell.org/trac/ghc/changeset/727d63c98e76f3a71b0e29ff5384a392a7bc6c36

>---------------------------------------------------------------

commit 727d63c98e76f3a71b0e29ff5384a392a7bc6c36
Author: Iavor S. Diatchki <iavor.diatchki at gmail.com>
Date:   Wed Mar 21 20:17:29 2012 -0700

    Fix the type of IsEven

>---------------------------------------------------------------

 GHC/TypeLits.hs |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/GHC/TypeLits.hs b/GHC/TypeLits.hs
index 06c05e2..cbbd015 100644
--- a/GHC/TypeLits.hs
+++ b/GHC/TypeLits.hs
@@ -174,8 +174,8 @@ instance Show (IsZero n) where
 
 data IsEven :: Nat -> * where
   IsEvenZero :: IsEven 0
-  IsEven     :: !(TNat (n+1)) -> IsEven (2 * (n + 1))
-  IsOdd      :: !(TNat n)     -> IsEven (2 * n + 1)
+  IsEven     :: !(TNat n) -> IsEven (2 * n + 2)
+  IsOdd      :: !(TNat n) -> IsEven (2 * n + 1)
 
 isEven :: TNat n -> IsEven n
 isEven (TNat n) | n == 0      = unsafeCoerce IsEvenZero