[Tex/LaTex] (fork) symbol for probabilistic causality? Logic

Question

I found pitchforks, but none that is similar to these explaines in Salmon 1989

Thanks!!

Answer 1

Since it should be a connective, the type is \mathbin; then we can use TeX's rules for relations:

\documentclass{article}

\newcommand{\fork}{%
  \mathbin{%
    \supset
    \mathrel{\mkern-9mu}%
    \mathrel{-}%
  }%
}

\begin{document}

The connective for the fork is $\fork$
and we can write $a\fork b$ or also
$a\fork_u b$.

\end{document}

Choose the kerning based on your liking.