I am using a custom document class risa as specified by a journal (available from: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291539-6924/homepage/ForAuthors.html. Download link: http://www.blackwellpublishing.com/pdf/risa.zip.). Seems like this class has a conflict with the amsthm package, because the use of \usepackage{amsthm} in the preamble gives an error: "Command \theoremstyle already defined." Hence, without using amsthm package, I am trying to remove some blank space that appears before and after a proposition. An MWE (which is quite long, sorry I couldn't find a better way to show the issue) is presented at the end.
My preamble is
\documentclass{risa}
\usepackage{graphicx}
\usepackage{natbib}
\usepackage{epstopdf}
\usepackage{tabularx}
\usepackage[figuresright]{rotating}
\usepackage{amsmath, amssymb}
\newtheorem{prop}{Proposition}
\usepackage{mathtools, cuted}
I use commands similar to:
...
\begin{prop}
Proposition 2 here
\end{prop}
\begin{proof}
Proof to Proposition 2 here
\end{proof}
...
There are 3 propositions, and the unwanted vertical space is observed only around Proposition 2. FYI, the risa class uses uses twocolumn page layout. I tried using \vspace{-1cm} etc. and tried changing the argument value, and found that low values (~0.5cm} did not produce any effect, but higher values (~1cm) made the Proposition jump up too much and overlap the preceding text. The closest answer I found was here: Remove vertical space around theorems, but that suggests using amsthm package which I cannot.
Please suggest whats wrong here. Thank you!
Edit added on Dec 27, 2016: I understood that an equation which appears on the top of the next column (given in the MWE) forces the Proposition environment to leave unwanted vertical space before and after. Please note that in there is only one Proposition in the MWE (not three as mentioned previously).
MWE:
\documentclass[sort&compress]{risa}
\usepackage{graphicx}
\usepackage{natbib}
\usepackage{url}
\urlstyle{same}
\usepackage{epstopdf}
\usepackage{tabularx}
\usepackage[figuresright]{rotating}
\usepackage{amsmath,amssymb}
\newtheorem{prop}{Proposition}
\setlength\theorempreskipamount{1pt plus 2pt minus1.5pt}% default: {12pt plus 5pt minus 3pt}
\setlength\theorempostskipamount{1pt plus 2pt minus1.5pt}% default: {8pt plus 3pt minus 1.5pt}
\usepackage{mathtools, cuted}
\begin{document}
\title[Title]{Title of the Article}
\author[Author]{First Last,$^{1}$\affiliation{Department, University}}
\begin{abstract}
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016-17). Welsh clubs that compete in the English football league system can also qualify.
The Premier League is a corporation in which the 20 member clubs act as shareholders. Seasons run from August to May. Teams play 38 matches each (playing each team in the league twice, home and away), totalling 380 matches in the season. Most games are played on Saturday and Sunday afternoons; others during weekday evenings. It is colloquially known as the Premiership and outside the UK it is commonly referred to as the English Premier League (EPL).
\end{abstract}
\begin{keywords}
keyword A, keyword B, keyword C
\end{keywords}
\maketitle
\pagebreak
\section{Introduction}
The Premier League\cite{1} is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016–17). Welsh clubs that compete in the English football league system can also qualify.
The Premier League is a corporation in which the 20 member clubs act as shareholders. Seasons run from August to May. Teams play 38 matches each (playing each team in the league twice, home and away), totalling 380 matches in the season. Most games are played on Saturday and Sunday afternoons; others during weekday evenings. It is colloquially known as the Premiership and outside the UK it is commonly referred to as the English Premier League (EPL).
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016–17). Welsh clubs that compete in the English football league system can also qualify.
The Premier League is a corporation in which the 20 member clubs act as shareholders. Seasons run from August to May. Teams play 38 matches each (playing each team in the league twice, home and away), totalling 380 matches in the season. Most games are played on Saturday and Sunday afternoons; others during weekday evenings. It is colloquially known as the Premiership and outside the UK it is commonly referred to as the English Premier League (EPL).
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016–17). Welsh clubs that compete in the English football league system can also qualify.
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016–17). Welsh clubs that compete in the English football league system can also qualify.
The Premier League is a corporation in which the 20 member clubs act as shareholders. Seasons run from August to May. Teams play 38 matches each (playing each team in the league twice, home and away), totalling 380 matches in the season. Most games are played on Saturday and Sunday afternoons; others during weekday evenings. It is colloquially known as the Premiership and outside the UK it is commonly referred to as the English Premier League (EPL).
\begin{prop}
\label{prop:epl}
The Premier League is (a) an English professional league for men's association football clubs,
(b) the country's primary football competition, and
(c) contested by 20 clubs.
\end{prop}
\begin{proof}
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016-17). Welsh clubs that compete in the English football league system can also qualify.
The Premier League is a corporation in which the 20 member clubs act as shareholders. Seasons run from August to May. Teams play 38 matches each (playing each team in the league twice, home and away), totalling 380 matches in the season. Most games are played on Saturday and Sunday afternoons; others during weekday evenings. It is colloquially known as the Premiership and outside the UK it is commonly referred to as the English Premier League (EPL).
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition.
\begin{eqnarray*}
\frac{\partial K}{\partial c_{a}} &=& \frac{u'_{a}(- c_{a}) }{ u_{a}(v_{a} - c_{a})-u_{a}(- c_{a})}\\
&-& \frac{[u_{a}(0)-u_{a}(- c_{a})](u'_{a}(- c_{a}) - u'_{a}(v_{a} - c_{a}))}{[ u_{a}(v_{a} - c_{a})-u_{a}(- c_{a})]^{2}},
\end{eqnarray*}
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016–17). Welsh clubs that compete in the English football league system can also qualify. \hfill $\blacksquare$
\end{proof}
\bigskip
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016–17). Welsh clubs that compete in the English football league system can also qualify.
The Premier League is a corporation in which the 20 member clubs act as shareholders. Seasons run from August to May. Teams play 38 matches each (playing each team in the league twice, home and away), totalling 380 matches in the season. Most games are played on Saturday and Sunday afternoons; others during weekday evenings. It is colloquially known as the Premiership and outside the UK it is commonly referred to as the English Premier League (EPL).
The Premier League is an English professional league for men's association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with the English Football League (EFL; known as "The Football League" before 2016–17). Welsh clubs that compete in the English football league system can also qualify.
The Premier League is a corporation in which the 20 member clubs act as shareholders. Seasons run from August to May. Teams play 38 matches each (playing each team in the league twice, home and away), totalling 380 matches in the season. Most games are played on Saturday and Sunday afternoons; others during weekday evenings. It is colloquially known as the Premiership and outside the UK it is commonly referred to as the English Premier League (EPL).
\bibliographystyle{vancouver}
\begin{thebibliography}{1}
\bibitem{1}
Wikipedia.org. Premier League; 2016. Available at: \url{https://en.wikipedia.org/wiki/Premier_League}, Accessed on December 27, 2016.
\end{thebibliography}
\end{document}
