Reducing 3CNF to Clique: Why do we omit negated literals? I have an example for a reduction of 3CNF to Clique, there is one thing I don't get about it, hopefully you could clarify it.  The reduction works like this:


  Construct a graph G = (V, E) as follows:
  
  Vertices: Each literal corresponds to a vertex.
  
  Edges: All vertices are connected with an edge except the vertices of
  the same clause and vertices with negated literals.


Why is it important that that negated literals will not be connected? How would that effect the reduction?
What is meant, is that literals that are the negation of each other are not connected. The reason for this is that they cannot both be satisfied at the same time. (The idea of the reduction is, that the graph contains a clique containing nodes corresponding to one literal from each clause, exactly if all these literals can be satisfied at the same time.)