1 files changed, 59 insertions, 1 deletions
diff --git a/src/packrat-graphs.ads b/src/packrat-graphs.ads
index cd5c364..76be2e4 100644
--- a/src/packrat-graphs.ads
+++ b/src/packrat-graphs.ads
@@ -252,7 +252,9 @@ package Packrat.Graphs is
 
     function Equal_Subgraph
            (Left, Right : in Cursor)
-        return Boolean;
+        return Boolean
+    with Pre =>
+            Is_Node (Left) and Is_Node (Right);
 
     function Subgraph_Node_Count
            (Position : in Cursor)
@@ -415,6 +417,54 @@ private
     subtype Node_Index is Positive;
     subtype Extended_Node_Index is Natural;
 
+
+
+
+    function Choices
+           (My_Graph : in Graph;
+            My_Index : in Node_Index)
+        return Natural
+    with Pre =>
+            My_Index <= My_Graph.Node_List.Last_Index;
+
+
+    procedure Delete_Loose_Subgraph
+           (Container : in out Graph;
+            Index     : in     Node_Index)
+    with Pre =>
+            Index <= Container.Node_List.Last_Index and then
+            Container.Node_List.Element (Index).Kind /= Null_Node;
+
+    procedure Delete_Up_Edge
+           (Container       : in out Graph;
+            Current, Parent : in     Node_Index)
+    with Pre =>
+            Container.Up_Edges.Contains (Current) and then
+            Container.Up_Edges.Reference (Current).Contains (Parent);
+
+    procedure Delete_Down_Edges
+           (Container : in out Graph;
+            From      : in     Node_Index;
+            Choice    : in     Positive)
+    with Pre =>
+            Container.Choices.Contains (From) and then
+            Container.Choices.Element (From) > 0 and then
+            Container.Down_Edges.Contains ((From, Choice)),
+        Post =>
+            not Container.Down_Edges.Contains ((From, Choice));
+
+
+    function Equal_Subgraph
+           (Left_Graph, Right_Graph : in Graph;
+            Left_Index, Right_Index : in Node_Index)
+        return Boolean
+    with Pre =>
+            Left_Index <= Left_Graph.Node_List.Last_Index and
+            Right_Index <= Right_Graph.Node_List.Last_Index;
+
+
+
+
     package Index_Vectors is new Ada.Containers.Vectors
        (Index_Type   => Positive,
         Element_Type => Node_Index);
@@ -422,6 +472,14 @@ private
 
 
 
+    function Node_Count
+           (Container : in Graph;
+            Root_List : in Index_Vectors.Vector)
+        return Natural;
+
+
+
+
     type Choice_Down is record
         From   : Extended_Node_Index;
         Choice : Natural;