Drawing a Hasse diagram in latex

Question

I am currently trying to draw the followig hasse diagram in Latex. From my undertsanding i think i should be using the tikzcd pacakge but having trouble getting undertstanding how it works. I would be grateful for any help.

Thank you in advance.

Answer 1

Here is a way to do it:

\documentclass{article}
\usepackage{amssymb} 
\usepackage{tikz-cd}

\begin{document}

\begin{tikzcd}[row sep=1.5cm, column sep=1.7cm]
& A \\
\{a, b\}\urar & \{a, c\}\uar \arrow[from=dr]& \{b, c\}\ular \\
\{a \}\uar\urar & \{b\}\ular[crossing over] \urar[crossing over] & \{ c\} \uar\\
 & \varnothing\ular\uar \urar
  \end{tikzcd} %

\end{document}