I've tried \vert, | , \mid but they produce vertical bars that are too tall. a \vDash is smaller than a vertical bar attached to an equal sign, so I've decided to give up on \vdash and it's evil spawn and just build my own symbols with |, \parallel, =, and \neq.
If you install the amssymb package and start your doc with "\usepackage{amssymb}" you'll have \vDash. A google search on "amssymb latex" will bring up a bunch of pages you can double check against before installing.
Mike -- gentoo-user@gentoo.org mailing list
