On Mon, Sep 18, 2006 at 12:23:11AM +0100, Ross Paterson wrote:
> To prove that (even for partial and infinite lists ps)
> 
>       splitSeq ps = [(a, seconds a ps) | a <- nub ps]
> 
> [...] we can establish, by induction on the input list,
> 
> (1)   fst (splitSeq' s ps) =
>               [(a, seconds a ps) | a <- nub ps, not (member a s)]
> (2)   member x s  =>
>               get x s (snd (splitSeq' s ps)) = seconds x ps

Oops, nub ps should be nub (map fst ps) in each case.

_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

Reply via email to