A.P. Young, at the University of Sussex, independently and simultaneously with Halperin and Nelson develops a distinct technical analysis of the same two-dimensional melting problem, using the formalism of a vector Coulomb gas instead of explicitly treating dislocations and disclinations as geometric defects. Despite the different technical tools, Young arrives at convergent conclusions about the existence of a two-stage melting transition mediated by topological defects. His work, published the same year and in the same volume of Physical Review B as Nelson and Halperin's, constitutes the third independent pillar of what the scientific community today knows as KTHNY theory, from the initials of its five contributors: Kosterlitz, Thouless, Halperin, Nelson, and Young.