December 31, 2007
This map lead to a conjecture in graph theory in 19th century which till now has not been proved “properly”. Although computerized exhaustive search proofs exist, mathemeticians reject it by calling it a “telephone directory” and they want the proof to be a “poem”.
Identify the conjecture/theorem/problem.
Happy New Year!
Cracked by: udupendra(Congratulations on scoring a century!) , jayanth , madhur , Dibyo , shenoyvarun86 , sumanth , sidsen , Ranjana Ninan , Shreyas , Keerthi , VikraM , piezocake , BiGFooT , nishas thambi , Gammafunction , prasanth , yaksha , Poornima , bobo , shashank and Arjun Chennu.
Quoting Arjun Chennu,
This is the Four Colour Problem identified by Francis Guthrie in 1852, when it was ‘discovered’ that any map could be colored using 4 colors such that adjacent segments received different colors.