\documentclass[10pt,a4paper]{report}
\usepackage[top=3cm, bottom=2.5cm, left=3cm, right=2.5cm] {geometry}
\usepackage {bsymb,b2latex}
\usepackage{fancyhdr,lastpage,color}
\lhead{\rm An Event-B Specification of MineContext}
\rhead {\rm Page \thepage~of \pageref{LastPage}}
\lfoot{}\cfoot{}\rfoot{}
\pagestyle{fancy}
%---------------------------------------------------------
\begin{document}
\thispagestyle{empty}
\begin{description}
\BTitle{MineContext}{16 Apr 2010}{02:22:11 PM}
\CONTEXT{MineContext}
\SETS
	\begin{description}
		\Item{ ONOFF }
		\Item{ LEVEL }
		\Item{ MINE\_SET }
	\end{description}
\CONSTANTS
	\begin{description}
		\Item{ ON }
		\Item{ OFF }
		\Item{ LOW }
		\Item{ MEDIUM }
		\Item{ HIGH }
		\Item{ M }
	\end{description}
\AXIOMS
	\begin{description}
		\nItemX{ axm1 }{ partition(ONOFF, \{ ON\} , \{ OFF\} ) }
		\nItemX{ axm2 }{ partition(LEVEL, \{ LOW\} , \{ MEDIUM\} , \{ HIGH\} ) }
		\nItemX{ axm3 }{ partition(MINE\_SET, \{ M\} ) }
	\end{description}
\END
\end{description}
\end{document}
