We study a model of graph related formulae that we call the \emph{Constraint-Graph model}. A constraint-graph is a labeled multi-graph (a graph where loops and parallel edges are allowed), where each edge $e$ is labeled by a distinct Boolean variable and every vertex is associate with a Boolean function over ... more >>>

We propose a new model for studying graph related problems that we call the \emph{orientation model}. In this model, an undirected graph $G$ is fixed, and the input is any possible edge orientation of $G$. A property is now a property of the directed graph that is obtained by a ... more >>>