Editing Chen's theorem (section)

== History ==
The [[theorem]] was first stated by [[China|Chinese]] [[mathematician]] [[Chen Jingrun]] in 1966,<ref>{{cite journal | last=Chen | first=J.R. | title=On the representation of a large even integer as the sum of a prime and the product of at most two primes | journal=Kexue Tongbao | volume=11 | issue=9 | year=1966 | pages=385–386}}</ref> with further details of the [[mathematical proof|proof]] in 1973.<ref name="Chen 1973">{{cite journal | last=Chen | first=J.R. | title=On the representation of a larger even integer as the sum of a prime and the product of at most two primes | journal=Sci. Sinica | volume=16 | year=1973 | pages=157–176}}</ref> His original proof was much simplified by P. M. Ross in 1975.<ref>{{cite journal | last=Ross | first=P.M. | title=On Chen's theorem that each large even number has the form (p<sub>1</sub>+p<sub>2</sub>) or (p<sub>1</sub>+p<sub>2</sub>p<sub>3</sub>) | journal=J. London Math. Soc. |series=Series 2 | volume=10,4 | year=1975 | pages=500–506 | doi=10.1112/jlms/s2-10.4.500 | issue=4}}</ref> Chen's theorem is a significant step towards [[Goldbach's  conjecture]], and a celebrated application of [[sieve theory|sieve methods]].

Chen's theorem represents the strengthening of a previous result due to [[Alfréd Rényi]], who in 1947 had shown there exists a finite ''K'' such that any even number can be written as the sum of a prime number and the product of at most ''K'' primes.<ref>[http://www-groups.dcs.st-and.ac.uk/history/Biographies/Renyi.html University of St Andrews - Alfréd Rényi]</ref><ref name="Alfréd Rényi 1948">{{cite journal | last=Rényi | first=A. A. | language=Russian | title=On the representation of an even number as the sum of a prime and an almost prime | journal=Izvestiya Akademii Nauk SSSR. Seriya Matematicheskaya | volume=12 | pages=57–78 | year=1948 }}</ref>