Re: double switch

Ah yes, how silly of me! Thanks,

Jon.

On Fri, 2005-02-25 at 22:03, Robert Hein wrote:
> Observe, that rule s is just the special case of s' with E=f.  The
> derivation you were looking for becomes
> 
>       ([R,U],T)
> =   -------------
>     ([R,U],[T,f])
> s'  --------------
>     [(R,T),[U,f]]
> =   --------------
>       [(R,T),U]
> 
> 
> 
> --Robert