Gabriel Andrew Dirac

Gabriel Andrew Dirac (13 March 1925 – 20 July 1984) was a Hungarian-British mathematician who mainly worked in graph theory. He served as Erasmus Smith's Professor of Mathematics at Trinity College Dublin from 1964 to 1966. In 1952, he gave a sufficient condition for a graph to contain a Hamiltonian circuit. The previous year, he conjectured that n points in the plane, not all collinear, must span at least ${\displaystyle \lfloor n/2\rfloor }$ two-point lines, where ${\displaystyle \lfloor x\rfloor }$ is the largest integer not exceeding ${\displaystyle x}$. This conjecture was proven true when n is sufficiently large by Green and Tao in 2012.