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

Question

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.

Answer 1

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.