Proof of four color theorem proved 


New Scientist reported that a 1976 proof of the famous four color theorem that involved a complicated computer program has itself been proved correct by translating the proof into a language where the steps of the proof can be checked by "logic-checking software". 

One wonders whether there is a proof that the translation was correct. Suppose that the researchers did achieve a translated program that is in fact a verifiable proof of the four color theorem. That alone does not prove that the original 1976 proof is correct, unless the process of translation has been shown not to have altered the logic of the original proof.

The four color theorem states that any flat map can be colored in a minimum of four colors where no two regions sharing a non-zero length boundary have the same color. 

Posted: Thursday - April 21, 2005 at 09:55 AM          

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