\newcommand{\implies}{\Rightarrow}                    % ==> (Claude).
\newcommand{\iffimplies}{\Longleftrightarrow}         % <==>

\newcommand{\map}{\rightarrow}                        % -->
\newcommand{\is}{\leftarrow}                          % <--
\newcommand{\injectif}{\hookrightarrow}               % injectif
\newcommand{\jacobi}[2]{\left(\frac{#1}{#2}\right)}   % Jacobi symbol
\newcommand{\legendre}[2]{\choose{#1}{#2}}            % Legendre symbol

\newcommand{\floor}[1]{\left\lfloor#1\right\rfloor}
\newcommand{\ceiling}[1]{\left\lceil#1\right\rceil}

\newcommand{\Plain}{\mathcal P}                       % for crypto
\newcommand{\C}{\mathcal C}
\newcommand{\K}{\mathcal K}
\newcommand{\E}{\mathcal E}
\newcommand{\D}{\mathcal D}
\newcommand{\T}{\mathcal T}

\newcommand{\F}[1]{{\cal F}_{#1}}
\newcommand{\GF}[1]{{\cal F}_{#1}}                    % Gallois Field
\newcommand{\BB}{\{0,1\}}                       

\newcommand{\SU}[1]{\it Strongly \, Universal_{#1}}   % Strongly Universal_n

\newcommand{\entr}[1]{\bf H({#1})}                      % H: Entropie    (Claude)
\newcommand{\info}[1]{\bf I({#1})}                      % I: Information (Claude)

\newcommand{\xor}{\oplus}                             % xor as a circled +.
\newcommand{\ou}{\vee}
\newcommand{\et}{\wedge}
\newcommand{\union}{\cup}
\newcommand{\inter}{\cap}

\def\bbN{{\rm I\kern-.23em N}}                        % Master Sayeki!
\def\bbP{{\rm I\kern-.25em P}}
\def\bbQ{{\rm\kern.24em \vrule width.02em height1.4ex depth-.05ex \kern-.26em Q}}
\def\bbR{{\rm I\kern-.25em R}}
\def\bbZ{{\rm\kern.26em \vrule width.02em height0.5ex depth 0ex \kern.04em \vrule width.02em height1.47ex depth-1ex \kern-.34em Z}}
