A new four-color theorem proof still needs a computer.

Mathematicians have long wanted proofs that explain why it is true.

Kenneth Appel and Wolfgang Haken’s original 1976 proof used a computer to check nearly 2,000 map configurations.

Whether any four-color proof can ever skip the computer check remains unresolved.

How each outlet framed it
Quanta Magazine
explores persistent mathematician dissatisfaction with 1970s computer-assisted proof; notes hunt for deeper theoretical insight

Sources: Quanta Magazine