Mathematical Structures: History of Rectangular bands

# History of Rectangular bands

 %%run pdflatex % \documentclass[12pt]{amsart} \usepackage[pdfpagemode=Fullscreen,pdfstartview=FitBH]{hyperref} \parindent=0pt \parskip=5pt \addtolength{\oddsidemargin}{-.5in} \addtolength{\evensidemargin}{-.5in} \addtolength{\textwidth}{1in} \theoremstyle{definition} \newtheorem{definition}{Definition} \newtheorem*{morphisms}{Morphisms} \newtheorem*{basic_results}{Basic Results} \newtheorem*{examples}{Examples} \newtheorem{example}{} \newtheorem*{properties}{Properties} \newtheorem*{finite_members}{Finite Members} \newtheorem*{subclasses}{Subclasses} \newtheorem*{superclasses}{Superclasses} \newcommand{\abbreviation}[1]{\textbf{Abbreviation: #1}} \pagestyle{myheadings}\thispagestyle{myheadings} \markboth{\today}{math.chapman.edu/structures} \begin{document} \textbf{\Large Rectangular bands} \quad\href{http://math.chapman.edu/cgi-bin/structures?action=edit;id=Rectangular_bands}{edit} \abbreviation{RBand} \begin{definition} A \emph{rectangular band} is a \href{Bands.pdf}{bands} $\mathbf{B}=\langle B,\cdot \rangle$ such that $\cdot$ is rectangular: $x\cdot y\cdot x=x$. \end{definition} \begin{definition} A \emph{rectangular band} is a \href{Bands.pdf}{bands} $\mathbf{B}=\langle B,\cdot \rangle$ such that $x\cdot y\cdot z=x\cdot z$. \end{definition} \begin{morphisms} Let $\mathbf{B}$ and $\mathbf{C}$ be rectangular bands. A morphism from $\mathbf{B}$ to $\mathbf{C}$ is a function $h:B\rightarrow C$ that is a homomorphism: $h(xy)=h(x)h(y)$ \end{morphisms} \begin{basic_results} \end{basic_results} \begin{examples} \end{examples} \begin{table}[h] \begin{properties} (\href{http://math.chapman.edu/cgi-bin/structures?Properties}{description}) \begin{tabular}{|ll|}\hline Classtype & variety\\\hline Equational theory & decidable in polynomial time\\\hline Quasiequational theory & \\\hline First-order theory & \\\hline Locally finite & yes\\\hline Residual size & \\\hline Congruence distributive & \\\hline Congruence modular & \\\hline Congruence n-permutable & \\\hline Congruence regular & \\\hline Congruence uniform & \\\hline Congruence extension property & \\\hline Definable principal congruences & \\\hline Equationally def. pr. cong. & \\\hline Amalgamation property & \\\hline Strong amalgamation property & \\\hline Epimorphisms are surjective & \\\hline \end{tabular} \end{properties} \end{table} \begin{finite_members} $f(n)=$ number of members of size $n$. $\begin{array}{lr} f(1)= &1\\ f(2)= &\\ f(3)= &\\ f(4)= &\\ f(5)= &\\ f(6)= &\\ f(7)= &\\ \end{array}$ \end{finite_members} \hyperbaseurl{http://math.chapman.edu/structures/files/} \parskip0pt \begin{subclasses}\ \href{Left-zero_semigroups.pdf}{Left-zero semigroups} \href{Right-zero_semigroups.pdf}{Right-zero semigroups} \end{subclasses} \begin{superclasses}\ \href{Normal_bands.pdf}{Normal bands} \end{superclasses} \begin{thebibliography}{10} \bibitem{Ln19xx} \end{thebibliography} \end{document} %
 %%run pdflatex % \documentclass[12pt]{amsart} \usepackage[pdfpagemode=Fullscreen,pdfstartview=FitBH]{hyperref} \parindent=0pt \parskip=5pt \addtolength{\oddsidemargin}{-.5in} \addtolength{\evensidemargin}{-.5in} \addtolength{\textwidth}{1in} \theoremstyle{definition} \newtheorem{definition}{Definition} \newtheorem*{morphisms}{Morphisms} \newtheorem*{basic_results}{Basic Results} \newtheorem*{examples}{Examples} \newtheorem{example}{} \newtheorem*{properties}{Properties} \newtheorem*{finite_members}{Finite Members} \newtheorem*{subclasses}{Subclasses} \newtheorem*{superclasses}{Superclasses} \newcommand{\abbreviation}[1]{\textbf{Abbreviation: #1}} \pagestyle{myheadings}\thispagestyle{myheadings} \markboth{\today}{math.chapman.edu/structures} \begin{document} \textbf{\Large Rectangular bands} \quad\href{http://math.chapman.edu/cgi-bin/structures?action=edit;id=Rectangular_bands}{edit} \abbreviation{RBand} \begin{definition} A \emph{rectangular band} is a \href{Bands.pdf}{bands} $\mathbf{B}=\langle B,\cdot \rangle$ such that $\cdot$ is rectangular: $x\cdot y\cdot x=x$. \end{definition} \begin{definition} A \emph{rectangular band} is a \href{Bands.pdf}{bands} $\mathbf{B}=\langle B,\cdot \rangle$ such that $x\cdot y\cdot z=x\cdot z$. \end{definition} \begin{morphisms} Let $\mathbf{B}$ and $\mathbf{C}$ be rectangular bands. A morphism from $\mathbf{B}$ to $\mathbf{C}$ is a function $h:B\rightarrow C$ that is a homomorphism: $h(xy)=h(x)h(y)$ \end{morphisms} \begin{basic_results} \end{basic_results} \begin{examples} \end{examples} \begin{table}[h] \begin{properties} (\href{http://math.chapman.edu/cgi-bin/structures?Properties}{description}) \begin{tabular}{|ll|}\hline Classtype & variety\\\hline Equational theory & decidable in polynomial time\\\hline Quasiequational theory & \\\hline First-order theory & \\\hline Locally finite & yes\\\hline Residual size & \\\hline Congruence distributive & \\\hline Congruence modular & \\\hline Congruence n-permutable & \\\hline Congruence regular & \\\hline Congruence uniform & \\\hline Congruence extension property & \\\hline Definable principal congruences & \\\hline Equationally def. pr. cong. & \\\hline Amalgamation property & \\\hline Strong amalgamation property & \\\hline Epimorphisms are surjective & \\\hline \end{tabular} \end{properties} \end{table} \begin{finite_members} $f(n)=$ number of members of size $n$. $\begin{array}{lr} f(1)= &1\\ f(2)= &\\ f(3)= &\\ f(4)= &\\ f(5)= &\\ f(6)= &\\ f(7)= &\\ \end{array}$ \end{finite_members} \hyperbaseurl{http://math.chapman.edu/structures/files/} \parskip0pt \begin{subclasses}\ \href{Left-zero_semigroups.pdf}{Left-zero semigroups} \href{Right-zero_semigroups.pdf}{Right-zero semigroups} \end{subclasses} \begin{superclasses}\ \href{Normal_bands.pdf}{Normal bands} \end{superclasses} \begin{thebibliography}{10} \bibitem{Ln19xx} \end{thebibliography} \end{document} %