\documentclass[a4paper]{article} 

\usepackage{amsmath,amsthm}
\usepackage{xcolor}
\usepackage[linkcolor=blue!50!black,colorlinks]{hyperref}
\usepackage{cleveref}

\newtheorem{theorem}{Theorem}

\let\d\undefined
\newcommand{\d}{\mathop{}\!\mathrm{d}}

\title{Vim\TeX{} test}
\author{Federico Stra}

\begin{document}

\maketitle

\begin{abstract}
Example document to experiment using Vim\TeX{}/\LaTeX{}Tools.
\end{abstract}

\tableofcontents

\section{Introduction}\label{sec:intro}

\begin{equation}\label{eq:basic}
	(1+1) + 1 = 1 + (1+1) % very simple
\end{equation}

% very important
\begin{theorem}[Euler]\label{thm:euler}
\begin{equation}\label{eq:euler}
	e^{2\pi i} = -1
\end{equation}
\end{theorem}

\begin{equation}
\alpha + \beta + \beta = \pi
\end{equation}

\[
	\int_0^\infty f(x) \d x
\]

\section{Conclusions}
\Cref{sec:intro}, \cref{thm:euler}, \eqref{eq:basic} and \eqref{eq:euler}.

\end{document}