[Tex/LaTex] Fuzzy logic operator symbols

Question

How can I write in Latex symbols for standard or Łukasiewicz conjunction like these?

Thank you

Answer 1

This keeps the "S" and "L" in non-italic upshape, as given in your example.

\documentclass{article}
\usepackage{stackengine}
\begin{document} 
$ a \mathrel{\stackunder[-1pt]{$\wedge$}{\tiny L}} 
  b \mathrel{\stackunder[-1pt]{$\wedge$}{\tiny S}} c$
\end{document}