Hi Kazu, On Tue, Aug 28, 2012 at 01:37:32PM +0900, Kazu Yamamoto wrote: > > I seems to us (my friends and me) that term rewriting rules for > ByteString are not fired in recent GHCs. Thanks for the report. I've filed a ticket here: http://hackage.haskell.org/trac/ghc/ticket/7374 Thanks Ian