How to specify display



Dear Stavros,

unfortunately, there was a *slight* misunderstanding:

Since graphs are usually rather large data-structures, I provided 
functions like edges(g), vertices(g), adjacency_matrix(g)...

But as usual output I'd like to have maxima print only the number of 
vertices and edges, its dimension (ie. is it a graph, a 3-graph, ... or 
a mixed hypergraph) and the name of the graph.

I will probably have a problem with my current internal format, which is

((%hypergraph) (prop1 . value1) (prop2 . value2) ...)

won't I ?

I don't think that it is necessary (or even wise) that a graph can be 
reconstructed from its output.

(not even wise, because as it is set up currently, a graph which is not 
assigned to a variable gets garbage collected, which is a good thing in my 
opinion)

eg:

(c1) complete_graph(5); 

(d1) "5 vertices, 10 2-edges"

and forget the graph. (Alternatively, assign it to d1, but I'm not sure 
whether this is a good idea)

(c1) z:complete_graph(5);

(d1) "5 vertices, 10 2-edges"

(c2) length(spanning_trees(z));

(d2) 125

Maybe its better to have a unique symbol assigned to each graph. I don't 
know.

Thanks a lot, 

Martin