The existence of unavoidable sets of geographically good configurations
نویسندگان
چکیده
منابع مشابه
Unavoidable Multicoloured Families of Configurations
Balogh and Bollobás [Combinatorica 25, 2005] prove that for any k there is a constant f(k) such that any set system with at least f(k) sets reduces to a k-star, an k-costar or an k-chain. They proved f(k) < (2k)2 k . Here we improve it to f(k) < 2ck 2 for some constant c > 0. This is a special case of the following result on the multi-coloured forbidden configurations at 2 colours. Let r be giv...
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بسیاری از پدیده ها در جهان ما اساساً غیرخطی هستند، و توسط معادلات غیرخطی بیان شده اند. از آنجا که ظهور کامپیوترهای رقمی با عملکرد بالا، حل مسایل خطی را آسان تر می کند. با این حال، به طور کلی به دست آوردن جوابهای دقیق از مسایل غیرخطی دشوار است. روش عددی، به طور کلی محاسبه پیچیده مسایل غیرخطی را اداره می کند. با این حال، دادن نقاط به یک منحنی و به دست آوردن منحنی کامل که اغلب پرهزینه و ...
15 صفحه اولAn Unavoidable Set of D-Reducible Configurations
We give a new proof of the four-color theorem by exhibiting an unavoidable set of 2822 D-reducible configurations. The existence of such a set had been conjectured by several researchers including Stromquist [18], Appel and Haken [2] and Robertson, Sanders, Seymour and Thomas [15].
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ژورنال
عنوان ژورنال: Illinois Journal of Mathematics
سال: 1976
ISSN: 0019-2082
DOI: 10.1215/ijm/1256049898