1前言保罗·埃尔德什(Paul Erds,1913-1996)是20世纪最具传奇色彩的数学家之一(图1[1]).他在60多年的数学研究生涯中,不停地奔波于各大洲的大学数学系和研究中心之间,与大量合作者共同发表了1500多篇学术论文[2];他的思维能力、工作热情无与伦比,直到古稀之年,他每天还工作19小时;他抛弃一切物质享受,甚至居无定所,追求数学真理就是他生命的一切. 1 Introduction Paul Erds (1913-1996) was one of the most legendary mathematicians of the 20th century (Figure 1 [1]). He spent 60 years in his mathematical studies career He traveled to the Department of Mathematics and Research Center of the University on all continents and co-published over 1,500 academic papers with a large number of collaborators [2]. His thinking ability and enthusiasm for work were unparalleled. Until the late 1970s, he worked 19 days a year Hour; he abandoned all material enjoyment, even without a fixed place, the pursuit of mathematical truth is everything of his life.