#LyX 2.4 created this file. For more info see https://www.lyx.org/
\lyxformat 600
\begin_document
\begin_header
\save_transient_properties true
\origin /systemlyxdir/doc/
\textclass scrartcl
\begin_preamble
\usepackage{ifpdf}

\ifpdf

\usepackage[colorlinks=true,
 pdftitle=Formelnummerierung, pdfpagemode=none,
 pdfpagelayout=OneColumn, pdfstartview=XYZ,
 pdfauthor={Uwe Stöhr},
 pdfsubject={LaTeX/LyX numbering example},
 pdfkeywords={LaTeX, numbering, LyX}]{hyperref}

\else % if DVI

\usepackage[colorlinks=true]{hyperref}

\fi

% define Roman counter
\newcounter{rom}
\renewcommand{\therom}{\roman{rom}}

% remember the original counter
\newcommand{\c@org@eq}{}
\let\c@org@eq\c@equation
\newcommand{\org@theeq}{}
\let\org@theeq\theequation

% \setrom activates the Roman counter
\newcommand{\setrom}{
  \let\c@equation\c@rom
  \let\theequation\therom}

% \setarab activates the original Arabic counter
\newcommand{\setarab}{
  \let\c@equation\c@org@eq
  \let\theequation\org@theeq}
% Added by lyx2lyx
\setlength{\parskip}{\medskipamount}
\setlength{\parindent}{0pt}
\end_preamble
\use_default_options false
\maintain_unincluded_children no
\language english
\language_package default
\inputencoding utf8
\fontencoding auto
\font_roman "default" "default"
\font_sans "default" "default"
\font_typewriter "default" "default"
\font_math "auto" "auto"
\font_default_family default
\use_non_tex_fonts false
\font_sc false
\font_sans_osf false
\font_typewriter_osf false
\font_roman_osf false
\font_sf_scale 100 100
\font_tt_scale 100 100
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\spacing single
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\use_package amsmath 2
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\cite_engine basic
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\justification true
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\index Index
\shortcut idx
\color #008000
\end_index
\secnumdepth 4
\tocdepth 3
\paragraph_separation indent
\paragraph_indentation default
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\end_header

\begin_body

\begin_layout Standard
This document demonstrates the usage of two different formula categories.
 One is Arabic, one is Roman numbered.
\end_layout

\begin_layout Standard
\begin_inset Formula 
\begin{equation}
A=B\label{eq:B}
\end{equation}

\end_inset


\begin_inset Formula 
\begin{equation}
A=C\label{eq:C}
\end{equation}

\end_inset


\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
setrom
\end_layout

\end_inset


\begin_inset Formula 
\begin{equation}
A=D\label{eq:D}
\end{equation}

\end_inset


\begin_inset Formula 
\begin{equation}
A=E\label{eq:E}
\end{equation}

\end_inset


\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
setarab
\end_layout

\end_inset


\begin_inset Formula 
\begin{equation}
A=F\label{eq:F}
\end{equation}

\end_inset


\begin_inset Formula 
\begin{equation}
A=G\label{eq:G}
\end{equation}

\end_inset


\begin_inset ERT
status collapsed

\begin_layout Plain Layout


\backslash
setrom
\end_layout

\end_inset


\begin_inset Formula 
\begin{equation}
A=H\label{eq:H}
\end{equation}

\end_inset


\begin_inset Formula 
\begin{equation}
A=I\label{eq:I}
\end{equation}

\end_inset


\end_layout

\begin_layout Standard
Cross-references: 
\begin_inset CommandInset ref
LatexCommand eqref
reference "eq:B"

\end_inset

 , 
\begin_inset CommandInset ref
LatexCommand eqref
reference "eq:C"

\end_inset

 , 
\begin_inset CommandInset ref
LatexCommand eqref
reference "eq:F"

\end_inset

 , 
\begin_inset CommandInset ref
LatexCommand eqref
reference "eq:G"

\end_inset

 , 
\begin_inset CommandInset ref
LatexCommand eqref
reference "eq:D"

\end_inset

 , 
\begin_inset CommandInset ref
LatexCommand eqref
reference "eq:E"

\end_inset

 , 
\begin_inset CommandInset ref
LatexCommand eqref
reference "eq:H"

\end_inset

 , 
\begin_inset CommandInset ref
LatexCommand eqref
reference "eq:I"

\end_inset


\end_layout

\begin_layout Standard
\noindent
\begin_inset CommandInset line
LatexCommand rule
offset "0.5ex"
width "100line%"
height "1pt"

\end_inset


\begin_inset VSpace medskip
\end_inset

To create this example, first a counter must be defined for the Roman numbered
 formulas.
 To do this the following is inserted to the \SpecialChar LaTeX
-preamble:
\end_layout

\begin_layout Standard

\series bold

\backslash
newcounter{rom}
\begin_inset Newline newline
\end_inset


\backslash
renewcommand{
\backslash
therom}{
\backslash
roman{rom}}
\end_layout

\begin_layout Standard
\begin_inset Newpage newpage
\end_inset

To save the value of the Arabic counter 
\series bold
equation
\series default
, this is added to the preamble
\end_layout

\begin_layout Standard

\series bold

\backslash
newcommand{
\backslash
c@org@eq}{}
\begin_inset Newline newline
\end_inset


\backslash
let
\backslash
c@org@eq
\backslash
c@equation
\begin_inset Newline newline
\end_inset


\backslash
newcommand{
\backslash
org@theeq}{}
\begin_inset Newline newline
\end_inset


\backslash
let
\backslash
org@theeq
\backslash
theequation
\end_layout

\begin_layout Standard
To be able to switch in the document between the two numbering schemes,
 the following commands are defined in the preamble:
\end_layout

\begin_layout Standard

\series bold

\backslash
newcommand{
\backslash
setrom}{
\backslash
let
\backslash
c@equation
\backslash
c@rom
\backslash
let
\backslash
theequation
\backslash
therom}
\end_layout

\begin_layout Standard
for Roman numbering and
\end_layout

\begin_layout Standard

\series bold

\backslash
newcommand{
\backslash
setarab}{
\backslash
let
\backslash
c@equation
\backslash
c@org@eq
\backslash
let
\backslash
theequation
\backslash
org@theeq}
\end_layout

\begin_layout Standard
for Arabic numbering.
\end_layout

\begin_layout Standard
Every formula will be by default numbered Arabic.
 To switch to Roman numbering, the command 
\series bold

\backslash
setrom
\series default
 is inserted in \SpecialChar TeX
-mode.
 With the command 
\series bold

\backslash
setarab
\series default
 the numbering is switched to Arabic.
\end_layout

\end_body
\end_document