# Negated Turnstile?

I wonder if anyone knows how can I produce negated turnstile symbols using the turnstile package. The default option of $\vdash$ and $\nvdash$ is not ok. I want the same options the turnstile package provides with a negated form.

• Please provide a MWE showing the issue. – Steven B. Segletes Nov 29 '17 at 15:51
• Have you tried $\not\vdash$? I'm not sure if this what you are looking for. A MWE would greatly help. – Ilbant Nov 29 '17 at 15:54

You could use \not in front of the \vdash for instance. However, the alignment of \not might not be centered. In this case use the package centernot with the command \centernot:

\documentclass{article}
\usepackage{amsmath}
\usepackage{turnstile}
\usepackage{centernot}
\begin{document}
$\begin{array}{lll} \not\vdash &\not\sststile{A}{B}&\Gamma \not\sdtstile{\mathrm{LC}}{x,y,z,w} P\\ [1em] \centernot\vdash&\centernot{\sststile{A}{B}}&\Gamma \centernot{\sdtstile{\mathrm{LC}}{x,y,z,w}} P \end{array}$
\end{document}


Edit: To get the \vdash and \nvdash , you could just load the amssymb package.

Where I've seen this in print, the negation is through the vertical bar of the turnstile. So I defined a command \nturn that takes the turnstile as its argument and overlays a (slightly raised) / symbol using \lefteqn.

Here is the code:

\documentclass{article}
\usepackage{amsmath,turnstile}

\newcommand{\nturn}[1]{\lefteqn{\raisebox{.2ex}{/}}\mathbin{#1}}

\begin{document}
$\Gamma \nturn{\sdtstile{\mathrm{L}}{x,y}} P\quad\Gamma \nturn{\sststile{\mathrm{LPD}}{x,y}} P$
\end{document}