[Tex/LaTex] Looking for a specific symbol used in set theory, can’t find on detexify

logicsymbols

I'm looking for a specific symbol for typesetting my lecture notes in logic and set theory.

The character is used to define a new set from two existing sets alpha and beta (which are ordinals):
Formula

In the above image, the \bot character is not what I want: instead of one vertical line I would like two parallel ones. Detexify found \coprod and \amalg (upside down product signs), which are close, but ideally the symbol that I'm looking for should be sans-serif.

In other words, I would like a symbol that is to \bot what \vDash is to \vdash. Unfortunately, I do not know the name of the operation that this symbol is representing, so meaning-based googling is ruled out.

Could anybody possibly help me out? I greatly appreciate your answers.

Best Answer

In the Comprehensive List (texdoc symbols) one can find something near to what you want, looking for \independent. Here's a modified version:

\documentclass{article}

\makeatletter
\DeclareRobustCommand{\varamalg}{%
  \mathbin{\mathpalette\var@malg\perp}%
}

\newcommand\var@malg[2]{%
  \rlap{$\m@th#1#2$}\mkern6mu{#1#2}%
}
\makeatother

\begin{document}
\[
\alpha\varamalg\beta=\alpha\times\{0\}\cup\beta\times\{1\}
\]
\end{document}

enter image description here

Adjust \mkern6mu to suit.