1.1 --- a/src/work/marci/graph_concept.h	Thu Apr 15 19:01:00 2004 +0000
     1.2 +++ b/src/work/marci/graph_concept.h	Thu Apr 15 20:19:26 2004 +0000
     1.3 @@ -364,8 +364,29 @@
     1.4      GraphSkeleturo(const GraphSkeleturo &G) {}
     1.5    };
     1.6  
     1.7 -  /// An empty graph class which provides a function to get the number 
     1.8 -  /// of its nodes.
     1.9 +  /// An empty node-eraseable graph class.
    1.10 +  
    1.11 +  /// An empty graph class which provides a function to 
    1.12 +  /// delete any of its nodes.
    1.13 +  class NodeEraseableGraphSkeleturo : public GraphSkeleturo
    1.14 +  {
    1.15 +  public:
    1.16 +    /// Deletes a node.
    1.17 +    void erase(Node n) {}
    1.18 +  };
    1.19 +
    1.20 +  /// An empty edge-eraseable graph class.
    1.21 +  
    1.22 +  /// An empty graph class which provides a function to delete any 
    1.23 +  /// of its edges.
    1.24 +  class EdgeEraseableGraphSkeleturo : public GraphSkeleturo
    1.25 +  {
    1.26 +  public:
    1.27 +    /// Deletes a node.
    1.28 +    void erase(Edge n) {}
    1.29 +  };
    1.30 +
    1.31 +  /// An empty graph class which provides a function to get the number of its nodes.
    1.32    
    1.33    /// This graph class provides a function for getting the number of its 
    1.34    /// nodes. 
    1.35 @@ -373,15 +394,14 @@
    1.36    /// function. For wrappers or graphs which are given in an implicit way, 
    1.37    /// the implementation can be circumstantial, that is why this composes a 
    1.38    /// separate concept.
    1.39 -  class NodeCountingGraphSkeleturo 
    1.40 +  class NodeCountingGraphSkeleturo : public GraphSkeleturo
    1.41    {
    1.42    public:
    1.43      /// Returns the number of nodes.
    1.44      int nodeNum() const { return 0;}
    1.45    };
    1.46  
    1.47 -  /// An empty graph class which provides a function to get the number of its 
    1.48 -  /// edges.
    1.49 +  /// An empty graph class which provides a function to get the number of its edges.
    1.50    
    1.51    /// This graph class provides a function for getting the number of its 
    1.52    /// edges. 
    1.53 @@ -389,7 +409,7 @@
    1.54    /// function. For wrappers or graphs which are given in an implicit way, 
    1.55    /// the implementation can be circumstantial, that is why this composes a 
    1.56    /// separate concept.
    1.57 -  class EdgeCountingGraphSkeleturo 
    1.58 +  class EdgeCountingGraphSkeleturo : public GraphSkeleturo
    1.59    {
    1.60    public:
    1.61      /// Returns the number of edges.