On 03/26/09 17:00, Andrew Sutton wrote:
IIRC, hypergraphs are only "undirected". An edge is represented as a set of vertices, that is, as an element of the powerset of vertices.
This is incorrect.
http://www.cis.upenn.edu/~lhuang3/wpe2/papers/gallo92directed.pdf
Hi Andrew and Om. This is a little off-topic, but I was wondering about an application. The application is representing Makefile dependencies. It seems that A target, Target (some vertex), would have a set of dependencies, Dep(Target) (a subset of the vertices), which could be represented by a hypergraph arc, E, (as defined on page 3 of gallo92directed.pdf, and where H(E) == {Target} and T(E) = Dep(Target)). Now if that hypergraph arc were labelled, then the label would represent the actions to produce the target from the dependencies. Now one added complication is that some labels may require "refinement". For example, boost build, when creating executables from object files, requires (AFAICT) all object files be produced with the same compiler. So, maybe for those labels requiring refinement, there could be some morphism to map each node in the hypergraph ending at an exectuable node to a "similar" hypergraph where each label has the same compiler or toolset in boost build terms. Maybe this could a future project building on this hypergraph project. -regards, Larry