You can always change this.

There was an old story. Two brothers, Juha and Jukka, both either always said truth or both always lied – but we do not know which was the case. Somebody asked them, whether they are married or not. Juha answered that at least one of them is married. Jukka then either answered that he is married, or he answered that he is not married – we do not know anymore, the story got twisted later, so nowadays there are two versions around. EDIT: version 1: Jukka said he is married, version 2: Jukka said he is not married.

Which of the versions is correct? We know for sure that, before garbling the story, the problem about what is the marital status of the brothers was correctly solved.

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Freely adapted from Raymond Smullyan. I am thinking about getting some of his books…