re: desugaring. Thanks Andrew, that worked great! I have another, easier question from the same code in RWH: bogusTransfer qty fromBal toBal = do fromQty <- atomically $ readTVar fromBal [snip] Can someone please explain the ($) function in English? From the type signature, it seems to be an "apply function", but I can't quite explain when we use it. Clearly, it is used throughout RWH but I haven't found a good explanation. My guess is that it is when we want an "execution" of a function rather than a mere reference to it. Is that accurate? thanks again Michael -- ---------------------- Michael Easter http://codetojoy.blogspot.com: Putting the thrill back in blog http://youtube.com/ocitv -> Fun people doing serious software engineering