{lyx} specifically is for questions about the LyX document-authoring application, that uses LaTeX for typesetting. Check that your problem isn't really a LaTeX problem before using this tag: export your file as LaTeX and try to compile this to find out.
LyX is a free open-source document processor that follows the WYSIWYM paradigm, which
- has an easy-to-use graphical user interface,
- shows graphical representations or previews of tables, math formulas, pictures, graphics within the LyX editor,
- automatically updates such summary material as table of contents, lists of figures, tables, equations, citations, and index entries, all through hyperlinks in the LyX editor, and
- offers a very usable change-tracking facility for collaborative editing.
The output of LyX is based on (La)TeX by default (though there are other options, such as output to XHTML). Hence, the writing of documents in LyX inherits the power and flexibility of (La)TeX.
For users accustomed to the traditional WYSIWYG document processing software, LyX provides a good opportunity to generate LaTeX documents without knowledge of LaTeX. For users who are already working with (La)TeX, the graphical representations of tables and math mode, the in-document-previews of graphics, and the options to change the document structure can be useful for fast authoring. Furthermore, several parts of the LyX editor are customizable.
