# What typeset does LyX use, and how to convert it to AmS-LaTeX (amsart)

I have a document in LyX, and I would like to convert the typeset to AmS-LaTeX (amsart) (if it is not in that form already). What typeset does LyX naturally use? Is there a way to do this directly on LyX or do I have to convert my document into a LyX file? In the latter case, how can I change the typeset to AmS-LaTeX (amsart)?

I'm not sure if this is useful, but when I go to Documents -> Settings, the Document class is set at "article." I notice that there is also "AMS article" but I am not sure if that's the same thing as amsart.

• AMS article will be `amsart.cls`. Yes.
– cfr
Oct 4, 2015 at 23:23
• @cfr Where do I go in LyX to insert that? Thanks. Which question does your "yes" refer too? >< Oct 5, 2015 at 2:14
• @TheSubstitute you were right about setting it in Document class. To see a .lyx file example using amsart, go to File > Open then click on the "Examples" button, then click on amsart-test.lyx. This works on Ubuntu at least. I know there is a different way to get to LyX's examples on Mac. Oct 5, 2015 at 3:47

I have a document in LyX, and I would like to convert the typeset to AmS-LaTeX amsart) (if it is not in that form already).

From a `.lyx` file:

1. Document > Settings ... > Document Class > article (AMS) > This select the LaTeX `amasart` document class.
2. May be you need edit the LyX text and/or the LaTeX preamble (also in Document > Settings ...) to be 100% compatible with `amsart` document class. The change of the document class, could left some LaTeX command undefined. In the best case Lyx will ignore the unkonw command and pass their argument as plain text, otherwise (for example, because is inside an ERT box), the command is passed to LaTeX code and produce a compilation error.
Also some packages as `relsize` in the preamble could be incompatible with the new document class. Your mileage may vary.

From a `.tex` file:

1. File > Import > LaTeX (plain) .... In complex documents some parts could be left as ERT boxes (your mileage may vary again).
2. Save the `.lyx` file and make the necessary changes as above.

Or may be better, make first the changes, then import:

1. With your text/LaTeX editor, change the document class to `amsart` (e.g. `\documentclass{article}` to `\documentclass{amsart}`)
2. Try to compile with `pdflatex`/`xelatex`/`lualatex`.
3. Remove/modify all source of errors, if any.
4. Save with `.tex` extension, go to Lyx and import this file (File > Import > LaTeX (plain) ...).

What typeset does LyX naturally use?

LyX write files with the `.lyx` extension in a special format, that has nothing to do with LaTeX.

Although many people think that LyX is a LaTeX editor, LyX is really a document preparation system that is, among other things, a very good LaTeX exporter (`.tex`). But if you select a DocBook document class, for example, the source is a `.lyx` file and the ouput is a .`xhtml` file, and both are not related with LaTeX in any form.