subscript for a join (\bowtie) operation in LyX/LaTeX

Question

I'm using LyX to write some Relational Algebra queries. I'm using the \bowtie symbol for the join operation but when I try to put a text in subscript directly under the symbol, I get the following error:

...a_{\t{pId}}\t{person}\right)\bowtie\limits {\t{pId}{1}=\t{pId}_{2}... I'm ignoring this misplaced \limits or \nolimits command.

Anyone knows how to do what I want? Preferably in LyX, but ERT code snippets will also be appreciated. Thanks!

Edit: \t is a macro for \text.

Clarke

Answer 1

Your problem is that \bowtie is not math operator such as \int, \sum etc.

Try this in preamble:

\usepackage{amsmath}
\DeclareMathOperator*{\btie}{\bowtie}

and this in document:

\(\btie\limits_{subscript}^{superscript}\)

I hope it's what you're looking for.

Hermaherman

More informations are here: ftp.ams.org/pub/tex/doc/amsmath/short-math-guide.pdf – Hermaherman

+1 - That's what I'd suggest too. There are many ways to make a new math operator, this is my preferred choice. – Plexor

Answer 2

Better use

\Join

It works fine for me

Unimposing

Answer 3

From http://en.wikibooks.org/wiki/LaTeX/Advanced_Mathematics#Above_and_below:

In preamble:

\usepackage{amsmath}

In equation:

\underset{your_subscript_here}{\bowtie}

Dinette