I am working on a model theory document in plain TeX, and I use the vdash and vDash symbols a lot.

\vdash is already part of plain TeX, so no problem, but what's the way to get \vDash to look consistent with it (same height, good alignment, etc.)?

> \vdash=\mathchar"3260.
> \vDash=undefined.

For the time being I use \def\vDash{\mathrel{|\!\!\!=}}, but that's ugly.

  • 2
    \input amssym and \vDash will do.
    – egreg
    Nov 16, 2022 at 17:36
  • @egreg This is great, thank you
    – Patrickkk
    Nov 16, 2022 at 17:45

2 Answers 2


The \vDash is common character in math, so it is supported in almost all Unicode math fonts. You can load Unicode math font and use it. For example in OpTeX:




The idea to load amssym is the way to old days when we didn't have Unicode.


The AMS provides support for its symbol font (the analog in LaTeX is \usepackage{amssym}.

The file to input is amssym.tex.

\input amssym

$A \vDash B$


enter image description here

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .