Textual Class Dictionary

  // Last Updated: 11/09/95  17:55 by carlos

Graph = "Class Dictionary Graph"
           < vertices > Vertex_List
           < edges > Edge_List .

Edge :   AltEdge
        | ConstEdge
        *common*
	"to"    < to > Vertex .

Edge_List ~ "Edge" "List" Edge  { Edge } .

Vertex_List ~ "Vertex" "List" Vertex  {  Vertex } .

Vertex :  AltVertex
        | ConstVertex
        *common*
           < vertexname > VertexName
          "vertex_pos" < position > Coordinates  .

AltEdge = "AltEdge"
	  "from"   < from > AltVertex .

ConstEdge = "ConstEdge"
           < edgename > EdgeName
"from"     < from > Vertex .

ConstVertex = "ConstVertex" .

AltVertex =  "AltVertex" .

Coordinates =  "("  < x > DemNumber ","
           < y > DemNumber  ")" .

VertexName =  < name > DemIdent
              "name_pos" < vn_position > Coordinates .

EdgeName =    < name > DemIdent 
	      "name_pos" < e_position > Coordinates .