🚀 go-pugleaf

kt> Wie kann ich LaTeX die Mengensymbole fuer natuerl.,
kt> reelle, komplexe, ganze usw Zahlen entlocken?


Nachdem die Frage in letzter Zeit oefter auftaucht, hier zwei geschnittene
Nachrichten zum gleichen Thema:


CK> Ich finde das Zeichen fuer |N, das N mit Doppelstrich, die Menge der
CK> natuerlichen Zahlen nicht.

------------CUT----------------------CUT----------------------CUT--------------

% Von  : Gregor Bautz
% Betr.: Re: Menge der natuerlichen Zah
-------------------------------------------------------------------------------
% natuerliche Zahlen
\def\N{\ifmmode%  Sind wir im Mathemodus ?
         \mathchoice{{\rm      I\hskip-2pt    N}}%     display-style
                    {{\rm      I\hskip -2pt   N}}%     text-style
                    {{\rm      I\hskip -1.5pt N}}%     scriptstyle
                    {{\rm      I\hskip -1pt   N}}%     scriptscriptstyle
       \else
         {\tenrm I\hskip-2pt N}
       \fi}

% reelle Zahlen
\def\R{\ifmmode%  Sind wir im Mathemodus ?
         \mathchoice{{\rm      I\hskip -2pt   R}}%     display-style
                    {{\rm      I\hskip -2pt   R}}%     text-style
                    {{\rm      I\hskip -1.5pt R}}%     scriptstyle
                    {{\rm      I\hskip -1pt   R}}%     scriptscriptstyle
       \else
                    {\tenrm I\hskip-2pt R}
       \fi}

% ganze Zahlen
\def\Z{\ifmmode%  Sind wir im Mathemodus ?
         \mathchoice{{\rm      Z\hskip -4pt Z}}%     display-style
                    {{\rm      Z\hskip -4pt Z}}%     text-style
                    {{\rm      Z\hskip -3pt Z}}%     scriptstyle
                    {{\rm      Z\hskip -3pt Z}}%     scriptscriptstyle
       \else
                    {\tenrm Z\hskip-4pt Z}
       \fi}

% komplexe Zahlen
\def\C{\ifmmode%  Sind wir im Mathemodus ?
         \mathchoice{{\rm      \vrule\hskip -3pt   C}}%    display-style
                    {{\rm      \vrule\hskip -3pt   C}}%    text-style
                    {{\rm      \vrule\hskip -3pt   C}}%    scriptstyle
                    {{\rm      \vrule\hskip -2pt   C}}%    scriptscriptstyle
       \else
         {\tenrm \vrule\hskip-3pt C}
       \fi}

------------------- cut ---------------------------------
Here are some nice little macros that will do the trick.

---- hier mit e'm wellenschlifigem messer endfernen ---
%************************************************************************
%* macro group: mathematics                                             *
%*                                                                      *
%* Erik Walter Quanstrom                                                *
%* 21. March 1990                                                       *
%*                                                                      *
%* macros:                                                              *
%*      Group symbols                                                   *
%*              \natural                natural numbers                 *
%*              \integer                integers                        *
%*              \complex                complex numbers                 *
%*              \rational               rational numbers                *
%*              \real                   real numbers                    *
%*              \imaginary              Imaginary numbers               *
%*                                                                      *
%*      Group relations                                                 *
%*              \norm                   Normal subgroup                 *
%*                                                                      *
%*      miscellainous                                                   *
%*              \mcr                    ragged right cr                 *
%*              \mod                    typesets a(mod b) properly      *
%*              \:                      no-space :                      *
%*              \qforall                \forall with padding            *
%*              \qexists                \exists with padding            *
%*                                                                      *
%************************************************************************
%
% the following macros are group symbols and they work in either math
% or normal mode.
\def\groupsym#1{%
        \ifmmode%
                \hbox{\msym #1}%
           \else%
                {\msym #1}%
        \fi}

\def\natural{\groupsum{N}}
\def\integer{\groupsym{Z}}
\def\rational{\groupsym{Q}}
\def\complex{\groupsym{C}}
\def\real{\groupsym{R}}
\def\poly{\groupsym{P}}
\def\imaginary{\groupsym{I}}
\def\identity{\groupsym{I}}
\def\I{\groupsym{I}}

\def\mcr{\hfill\cr}
\def\norm{\triangleleft}
\def\mod{%
        \ifmmode%
                $mod $%
           \else%
                mod\,%
        \fi}

\def\qforall{\,\forall\,}
\def\qexists{\,\exists\,}
\def\:{\colon}

% define a shorthand for such that.
\def\st{%
        \ifmmode%
                ${\rm\ s.t. }$%
           \else%
                {\rm\ s.t. }%
        \fi}
--
%-----cut here with a sharp machete or an 19.95 ginsu knife