\documentclass[11pt]{article} \usepackage{fullpage} \usepackage{url} \usepackage{amsmath} % This is a file of macros and definitions that may come up in % ANY LATEX paper. Typically I'll use this file and some other file in the % directory of the paper, this one for general math things, that one for % things specific to that paper. % % font's used and general paper things. \font\tenrm=cmr10 \font\ninerm=cmr9 \font\eightrm=cmr8 \font\sevenrm=cmr7 % \font\title=cmbx10 scaled \magstep1 % extra big title font \font\ss=cmss10 % used by \proof \font\smallcaps=cmcsc10 % used to label Theorems, etc. % imhibit black bars on overflows % \overfullrule=0pt % % today's date % % % English words that I always italizice in papers. % Some words that appear in math mode alot that I wasn roman % \newcommand{\AREA}{{\rm AREA}} \newcommand{\ALG}{{\rm ALG}} \newcommand{\ACK}{{\rm ACK}} \newcommand{\VC}{{\rm VC}} \newcommand{\AC}{{\rm AC}} \newcommand{\ZL}{{\rm ZL}} \newcommand{\WOP}{{\rm WOP}} \newcommand{\tree}{{\rm tree}} \newcommand{\SUBSEQ}{{\rm SUBSEQ}} \newcommand{\minor}{{\preceq_m}} \newcommand{\minorp}{{\preceq_m'}} \newcommand{\cminor}{{\preceq_{\rm c\hbox{-}m}}} \newcommand{\GM}{{\rm GM}} \newcommand{\TREE}{{\rm TREE}} \newcommand{\R}{\rm R} \newcommand{\B}{\rm B} \newcommand{\G}{\rm G} \newcommand{\Y}{\rm P} \newcommand{\IO}{\exists^\infty} \newcommand{\ceil}[1]{\left\lceil {#1}\right\rceil} \newcommand{\floor}[1]{\left\lfloor{#1}\right\rfloor} \newcommand{\into}{{\rightarrow}} \newcommand{\D}{{\sf D}} \newcommand{\N}{{\sf N}} \newcommand{\Z}{{\sf Z}} \newcommand{\Q}{{\sf Q}} \newcommand{\reals}{{\sf R}} \newcommand{\qd}{{\rm qd}} \newcommand{\GE}[1]{{\equiv^{G}_{#1}}} \newcommand{\TE}[1]{{\equiv^{T}_{#1}}} \newcommand{\TES}[1]{{\equiv^{T}_{#1,{\rm S}}}} \newcommand{\TEB}[1]{{\equiv^{T}_{#1,{\rm BOOL(S)}}}} \newcommand{\LL}{{\cal{L}}} \newcommand{\onepe}{1+\epsilon} \newcommand{\oneme}{1-\epsilon} \newcommand{\cool}{cool} \newcommand{\nze}{numzeros} \newcommand{\non}{numones} \newcommand{\LR}[2]{ {\rm LR}_{{#2}}({#1})} \newcommand{\LH}[2]{ {\rm LH}({#1};{#2})} \newcommand{\bbb}{{\gamma}} \newcommand{\COL}{{\rm COL}} \newcommand{\card}[1]{\#(#1)} \newcommand{\st}{\mathrel{:}} \newcommand{\fhat}{{\hat{f}}} \newcommand{\Ahat}{{\hat{A}}} \begin{document} \centerline{\bf Homework 08, Morally Due 12:30PM, Tue Apr 7 2026} \newif{\ifshowsoln} %\showsolntrue % comment out to NOT show solution inside \ifshowsoln and \fi blocks. \begin{enumerate} \item (0 points) What is your name? \vfill \centerline{\bf GO TO NEXT PAGE} \newpage \item (30 points) Let $\COL \colon \binom{[n]}{2} \into [\omega]$. Assume that, for all colors $c$, for all $x\in [n]$, $\deg_c(x)\le 17$. Show that there is a rainbow set of size $\Omega(n^{1/3})$. \vfill \centerline{\bf GO TO NEXT PAGE} \newpage \item (40 points) {\bf Recall:} we showed the following: For all $f\colon \Z\times \Z \into \Z$ there exists infinite $\D\subseteq \Z$ such that $f$ restricted to $\D\times\D$ is NOT onto. Recall that we used the 1-ary Ramsey Theorem ONCE and the 2-ary Ramsey Theorm TWICE. We could that as THREE uses of Ramsey's Theorem. And NOW for our problems \begin{enumerate} \item Let $f\colon \Z\times \Z \times \Z \into \Z$. Show there exists a $\D\subseteq \Z$ such that $f$ restricted to $\D\times\D\times\D$ is not onto. How many times does your proof use the Ramsey's theorem? \item Let $a\in\N$. Let $f\colon \Z^a\into \Z$. Show there exists a $\D\subseteq \Z$ such that $f$ restricted to $\D^a$ is not onto. Let $g(a)$ be the number of times your proof uses the Ramsey's theorem. If you did the problem correctly then $g(a)$ does not have a nice closed form but it is the solution to a combinatorial problem. What is that problem? \end{enumerate} \vfill \centerline{\bf GO TO NEXT PAGE} \newpage \item (30 points) {\bf Recall} that a finite set $X$ is {\it Large} if $|X|>\min(X)$. Prove the following: {\it For all $k$, there exists an $n$, such that, for all $\COL\colon \binom{\{k,k+1,\ldots,k+n\}}{2}\into [\omega]$ there is a large set that is either \begin{itemize} \item homog \item min-homog \item max-homog \item rainbow \end{itemize} } \vfill \centerline{\bf GO TO THE NEXT PAGE} \newpage \item (0 points, but you must answer it) As you all know, Yasmine's stage name is {\it Bad Sequence}. If I had a rock band I would call it {\it The Red Cliques}. A grad student in quantum computing had a group called {\it Amplitudes with Attitude}. Dave Mount (Geometry) would name his group {\it Fried Green Ellipsoids}. The following are real groups: {\it The Mobius Band}, {\it The Klein Four}, {\it The MIT Logarhythms}. There is a rap singer named MC++. There is subgenre of rap called {\it Nerdcore} where people sing about math and technology things. {\it Drama in the PhD} is the best example of that. Do not confuse this with {\it mathcore} which is {\it a highly technical, chaotic subgenre of hardcore punk and metalcore} which in my opinion is just noise. \bigskip OKAY, so finally here is the question: If you had a stage name, what would it be? If you had a rock group, what would you name it? \end{enumerate} \end{document}