@Pierre

This would look like this:

I have been using this to create a plot of a network:

$graph=plotmaple("plottools[rotate](GraphTheory[DrawNetwork](GraphTheory[Digraph]($cove),stylesheet=[arrowsize = 18]),Pi)");

The reason I rotate is because I was initially interested in plotting a Hasse diagram. However, it seems the DrawNetwork function does not really draw an acyclic graph by levels: an acyclic graph can be associated with a poset and as a consequence can be displayed by levels like in a Hasse Diagram, where the vertices with no ingoing arcs are displayed at the bottom level, then once these vertices are removed the remaining vertices with in-degree 0 are placed at the next level, and so on until all the vertices have ben placed. I would be grateful if there was a solution for this.

However the other issue is that I don't seeem to be able to reduce the thickness of the lines drawn. I tried the option thicness = 0 as part of the stylesheet list with no avail. The image is as follows:

If I could create a proper Hasse diagram this would look like this:

I have come to realise there are limitations on what mapleplot can do, but I have not found a clear documentation about it. I'll repost a question on what I am trying to do in the other forum about writing questions.

What version of Maple is used by the API? I created a library that uses the GraphTheory package of Maple2021. It seems the Maple API does not use this package as it does not recognise various options, e.g. it does not accept loops in digraphs,and does not accept the selfloops parameter, and it does not recognise the network option when drawing graphs.

I'll be grateful if someone could shed light on that.