%auto-ignore \usepackage{theorem} \usepackage[english]{babel} \usepackage{a4} \usepackage{epsfig} \usepackage{amsfonts} \usepackage{latexsym} \newtheorem{theorem}{Theorem} \newtheorem{lemma}[theorem]{Lemma} \newtheorem{proposition}[theorem]{Proposition} \newtheorem{corollary}[theorem]{Corollary} \newtheorem{algorithm}[theorem]{Algorithm} \newtheorem{definition}[theorem]{Definition} \theorembodyfont{\rmfamily} \newtheorem{remark}[theorem]{Remark} \theorembodyfont{\rmfamily} \newtheorem{example}[theorem]{Example} \newenvironment{proof}[1][\it Proof.]{\begin{trivlist}\item[\hskip \labelsep {\bfseries #1}]}{$_\Box$\end{trivlist}} \def\N{\ensuremath{\mathbb{N}}} \def\Z{\ensuremath{\mathbb{Z}}} \def\Q{\ensuremath{\mathbb{Q}}} \def\R{\ensuremath{\mathbb{R}}} \def\F{\ensuremath{\mathcal{F}}} \def\G{\ensuremath{\mathcal{G}}} \def\K{\ensuremath{\mathcal{K}}} \def\k{\ensuremath{{\bf{k}}}} \def\x{\ensuremath{{\bf{x}}}} \def\t{\ensuremath{{\bf{t}}}}