Christof,

Agree with everything you say. Having read all the replies I too have
been wondering if I'd missed something !

Michel.

====================== Original message follows ====================

>Hi Vlad,
>
>>You use the info from the previous days to distinguish. The inductive method works.
>
>Then I must have misread the original question. If I use information from the previous day, those information must be different from todays information, otherwise I've an infinite loop. And this requires that the number of green or red smurfs decreases over the time. But since for every green smurf the situation is the same, no-one can start saying "I'm a green smurf". WHat did I miss?
>
>Christof