[Tex/LaTex] How to cross reference theorem lemma etc as for example “Theorem 1” in LyX

cross-referencinglyxtheorems

I have loaded the theorem by type and theorem by type within Chapter (TIP for learner:add the first in order to add the second).

So I use theorem environment for different types: proposition, corollary, lemma etc.

I cannot find solution how to cross reference them in the format of "Proposition 1.1". The manual does not help either. Please provide a learner-friendly step-by-step guide! (For example, do I need to load anything to the default LyX first? Which LaTeX code has to be pasted etc? )

Urgent help needed as my thesis deadline is one week later!

The following shows why I got stuck:

1: Under corollary environment, I click right after the Corollary 1.1 and insert a label, LyX automatically shows "Under-the-same" in lable context, so I changed it into Corollary 1.3

2: I insert cross reference in the text as "formatted reference".

3: The cross reference result in PDF does not include "Corollary" caption, only 1.3:

Update: I just found that this normal under auto cross-references which is used by Classicthesis template, according to its explanation:

So I just want to know how to input the reference label manually so that it shows "Proposition 1.1" in color in PDF? Or the ultimate solution by changing LaTeX code in the config file it it is not too complex?

UPDATE for learners

I just realized that I can change the style of crossreference in document->setting->pdf properties-> tick "customize hyperref options"->hyperlinks. You can delete the red frame or make them in color or without color!

Best Answer

You need to Insert>Label within your theorem or corollary. Let's say the label is cor:myprecious. It might be that autorefname hasn't been defined for these environments, so you'll have to add

\providecommand{\thmautorefname}{Theorem}
\providecommand{\corautorefname}{Corollary}
\providecommand{\lemautorefname}{Lemma}

either to classicthesis-config.tex (say, around line 230) or your Document>Settings>Preamble You will then insert an autoreference either in a TeX box (ctrl-L) \autoref{cor:myprecious} or by using a custom inset as described in the manual (screenshot above)

Related Solutions

[Tex/LaTex] Using the xr package in LyX (for cross-referencing an external LyX document)

I have been trying to get xr and xcite working for past couple days in LyX and this post and the links it cites were about all I could find as references. Since the current answer doesn't fully explain what is going on in LyX, I'll give what works for me for using xr (or xcite) with LyX:

Put
```
\usepackage{xr}
\externaldocument{referenced}
```
into the LaTeX preamble in Document->Settings of the referencing document (I will call it referencing.lyx).
Build the referenced document to obtain referenced.aux.

You can either do File->Export to export referenced.tex and run latex on it to generate referenced.aux or you build the document normally in LyX with the View command. If you use the View command, you will need to find LyX's temporary directory where it ran latex. This directory should be a subdirectory of the Temporary directory listed under the Paths section of LyX's Preferences. The LyX subdirectories (there might be more than one depending on how many document you have opened and rendered during the session) will have names starting with lyx_tmpdir and will contain subdirectories with names beginning with lyx_tmpbuf. One of these lyx_tmpbuf directories should contain referenced.aux (if you start a new LyX session and View referenced.lyx, it should be easy to find since there shouldn't be a lot of extra LyX directories). (Itai, LyX's temporary directory is usually located in a system temporary directory that does not show up in typical file searches, so that might be why you could not find any .aux files).
Once you have referenced.aux, just save it in the same directory as referencing.lyx and LyX should find it when it renders referencing.pdf.

Other usage notes:

LyX does not have native support for xr or xcite. Initially, the labels in referenced.lyx will not appear as options in the cross-reference dialog in LyX. To reference items from referenced.lyx such as referenced_label1, you can either do "Insert->TeX Code" and put \ref{referenced_label1} in by hand, or you can keep referenced.lyx open, right-click on the label you want to reference and choose "Copy as reference", and then paste into referencing.lyx at the point where you want to make the reference.
Because LyX does not have support for xr, pasted labels will show up in LyX with a BROKEN: prefixed in front of the label. However, they should still be rendered properly in the pdf that is produced. The BROKEN: prefix just means that LyX can't find that label defined within referencing.lyx. One way to get around this is to put referencing.lyx as a child document (Insert -> File -> Child Document) within a LyX note. Then its labels will show in the cross-reference dialog in LyX, but because the inclusion is within a LyX note, it won't get rendered in the .pdf.
Pasted labels will appear in LyX's cross-reference dialog (as BROKEN: references). Don't try to reference them from there though because you end up with a reference to a reference.
With xcite, if you have a separate .bib file for referenced.lyx (call it referenced.bib), you can add referenced.bib to referencing.lyx's bibliography and cite the items normally (rather than copying and pasting references out of referenced.lyx). Then, when you want to render the referencing.pdf, remove referenced.bib from the bibliography. This should break all of the citations within referencing.lyx but they should still be found by xcite.
While searching for how to use xr with LyX, I saw references to a combo document option in LyX that would allow it to use the same temporary directory for two LyX files (in which case referenced.aux file could be made available to referencing.lyx without having to put it in the working directory as described above). As far as I can tell, this feature was removed before LyX 2.0 and is not an option any more.

[Tex/LaTex] Lyx 2.0 Formatted references to theorem/lemma/claim environments

Add to the document preamble (Document --> Settings --> LaTeX preamble)

\newref{claim}{name=claim~}

and it will probably work. As mentioned by egreg in the comments, the refstyle package is used, and you have to tell it what it should insert for labels starting with claim:.

refstyle also provides commands for start-of-sentence references (capital letter) and plural forms, and the words to insert in these cases can also be specified, e.g.

\newref{claim}{name=claim~,Name=Claim~,names=claims~,Names=Claims~}

I don't know, however, how to make LyX use these, other than through using an ERT, with e.g. \Claimref{claim:1}. See the refstyle documentation for details.

Example

Copy the following code to an empty file and save as a .lyx file, e.g. example.lyx. Open in LyX and compile. Screenshots of LyX view and PDF below.

#LyX 2.0 created this file. For more info see http://www.lyx.org/
\lyxformat 413
\begin_document
\begin_header
\textclass article
\begin_preamble
\newref{claim}{name=claim~}
\end_preamble
\use_default_options true
\begin_modules
theorems-bytype
theorems-sec-bytype
\end_modules
\maintain_unincluded_children false
\language english
\language_package default
\inputencoding auto
\fontencoding global
\font_roman default
\font_sans default
\font_typewriter default
\font_default_family default
\use_non_tex_fonts false
\font_sc false
\font_osf false
\font_sf_scale 100
\font_tt_scale 100

\graphics default
\default_output_format default
\output_sync 0
\bibtex_command default
\index_command default
\paperfontsize default
\spacing single
\use_hyperref false
\papersize default
\use_geometry false
\use_amsmath 1
\use_esint 1
\use_mhchem 1
\use_mathdots 1
\cite_engine basic
\use_bibtopic false
\use_indices false
\paperorientation portrait
\suppress_date false
\use_refstyle 1
\index Index
\shortcut idx
\color #008000
\end_index
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\paragraph_indentation default
\quotes_language english
\papercolumns 1
\papersides 1
\paperpagestyle default
\tracking_changes false
\output_changes false
\html_math_output 0
\html_css_as_file 0
\html_be_strict false
\end_header

\begin_body

\begin_layout Section
Something
\end_layout

\begin_layout Claim
\begin_inset CommandInset label
LatexCommand label
name "claim:claim1"

\end_inset

I hereby claim that I don't use LyX.
\end_layout

\begin_layout Theorem
\begin_inset CommandInset label
LatexCommand label
name "thm:1"

\end_inset

LyX makes some things harder.
\end_layout

\begin_layout Standard
Inserting references: 
\begin_inset CommandInset ref
LatexCommand formatted
reference "thm:1"

\end_inset

 and 
\begin_inset CommandInset ref
LatexCommand formatted
reference "claim:claim1"

\end_inset

.

\end_layout

\end_body
\end_document

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