Theorem in quote environment [duplicate]

Question

I would like to use a theorem-like environment inside a quote environment (or with the same spacing as a quote environment).

In this answer the following solution is presented:

\documentclass{article}
\usepackage{amsthm}
\usepackage{lipsum}

\theoremstyle{definition}
\newtheorem{theo}{Theorem}
\newenvironment{Qtheorem}[1][]
  {\quote\begin{theo}[#1]}
  {\end{theo}\endquote}

\begin{document}

\lipsum[1]
\begin{Qtheorem}
\lipsum[1]
\end{Qtheorem}
\lipsum[1]

\end{document}

However, it produces extra/unwanted space at the top of the environment:

Can this be fixed directly?

Answer 1

You could define your own style:

\documentclass{article}
\usepackage{amsthm}
\usepackage{lipsum}

\newtheoremstyle{mystyle}%
{0pt}%space above
{0pt}%space below
{}% body font
{}% paragraph indent amount
{\bfseries}% head font
{.}% punctuation after head
{.5em}% space after head
{}% headspec

\theoremstyle{mystyle}
\newtheorem{theo}{Theorem}
\newenvironment{Qtheorem}[1][]
  {\quote\begin{theo}[#1]}
  {\end{theo}\endquote}

\begin{document}

\lipsum[1]
\begin{Qtheorem}
\lipsum[1]
\end{Qtheorem}
\lipsum[1]

\end{document}