diff --git a/dump.cpp b/dump.cpp
deleted file mode 100644
index 1da2466..0000000
--- a/dump.cpp
+++ /dev/null
@@ -1,230 +0,0 @@
-// Ah... The joys graph data structures :)
-// A hole into which many a good computer scientist has fallen, never to be heard from again.
-//					- Andrew Sutton
-
-/*
-	Basic idea: provide concepts that define the interface(s) to different kinds of graphs so that you can do
-	basic graph operations and algorithms without knowing exactly which kind of graph it is and keep ignorant
-	about implementation details.
-    
-    Basic design idea: do like the STL
-*/
-
-/*
-// Graph concepts (like STL containers):
-// Do we need them (STL doesn't make containers explicit)
-template<class G> concept bool Graph = false; // general graph operations
-template<class G> concept bool DAG = false;	 // operations simplified for DAGs (any extra operations?)
-template<class G> concept bool Tree = false;	 // operations simplified for trees (any extra operations?)
-
-// accessor concepts (like STL Iterators):
-template<class G> concept bool Edge_ref = false;	     // most general and slowest
-template<class G> concept bool DAG_edge_ref = false;	 // operations simplified for DAGs (any extra operations?)
-template<class G> concept bool Tree_edge_ref = false; // operations simplified for trees (any extra operations?)
-
-template<class G> concept bool Vertex_ref = false;      // most general and slowest
-template<class G> concept bool DAG_vertex_ref = false;  // operations simplified for DAGs (any extra operations?)
-template<class G> concept bool Tree_vertex_ref = false; // operations simplified for DAGs (any extra operations?)
-
-// the value type (in a more general design, this would be a template parmeter):
-struct Val {};
-
-// specific directed graphs:
-struct Tree {};
-struct Dag { };
-struct Dgraph {};
-
-struct Node_ref {};
-struct Edge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-struct DAG_vertex_ref {};
-struct DAG_edge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-struct Gnode_ref {};
-struct Gedge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-// another Graph representation:
-struct DGN_ref {};
-struct DGE_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-// use:
-template<Graph G>
-void traverse(G& g)
-{
-	vector<???> found;	// there is a way (look up traits), lets try g::value_type
-}
-
-*/
-
-/*
-	Basic idea: provide concepts that define the interface(s) to different kinds of graphs so that you can do
-	basic graph operations and algoriths without knowing exactly which kind of graph it is and keep ignorant
-	about implementation details.
-    
-    Basic design idea: do like the STL
-*/
-
-/*
-// Graph concepts (like STL containers):
-// Do we need them (STL doesn't make containers explicit)
-template<class G> concept bool Graph =  // general graph operations
-	requires { typename G::value_type; };
-template<class G> concept bool DAG = Graph<G> && requires(G g) { tops(g); };	 // operations simplified for DAGs 
-template<class G> concept bool Tree = DAG<G> && requires(G g) { top(g); };	 // operations simplified for trees
-
-// accessor concepts (like STL Iterators):
-template<class E> concept bool Edge_ref =      // most general and slowest
-	requires { typename E::value_type; };
-template<class E> concept bool DAG_edge_ref = // operations simplified for DAGs (any extra operations?)
-	Edge_ref<E> && false;	 
-template<class E> concept bool Tree_edge_ref = // operations simplified for trees (any extra operations?)
-	DAG_edge_ref<E> && false; 
-
-template<class G> concept bool Vertex_ref = true;      // most general and slowest
-template<class G> concept bool DAG_vertex_ref = false;  // operations simplified for DAGs (any extra operations?)
-template<class G> concept bool Tree_vertex_ref = false; // operations simplified for DAGs (any extra operations?)
-
-// the value type (in a more general design, this would be a template parmeter):
-struct Val {};
-
-// specific directed graphs (note: we can't assume common structure or common naming from implementation):
-struct Tree {
-  	using value_type = Val;
-};
-
-struct Node_ref {};
-struct Edge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-void tops(Tree&);	// return vector Tree_vertex_refs
-Node_ref top(Tree&);
-
-struct Dag {
-  	using value_type = Val;
-};
-
-struct DAG_vertex_ref {};
-struct DAG_edge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-void tops(Dag&);
-
-struct Dgraph {
-  	using value_type = Val;
-};
-
-
-struct Gnode_ref {};
-struct Gedge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-// another Graph representation:
-struct DGN_ref {};
-struct DGE_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-// use:
-#include <vector>
-using namespace std;
-
-template<Graph G, Vertex_ref R>
-void traverse(G& g, R r)
-{
-	vector<typename G::value_type> found;	// member g::value_type (old habit: could just have used Val)
-  	// ... 
-}
-
-void use1(Tree& t, Dag& d, Dgraph& dg, Node_ref& tr, DAG_vertex_ref& dr, Gnode_ref& gr)
-{
-  traverse(t,tr);
-  traverse(d,dr);
-  traverse(dg,gr);
-}
-
-*/
-
-
-/*
-	Basic idea: provide concepts that define the interface(s) to different kinds of graphs so that you can do
-	basic graph operations and algoriths without knowing exactly which kind of graph it is and keep ignorant
-	about implementation details.
-    
-    Basic design idea: do like the STL
-*/
-/*
-// Graph concepts (like STL containers):
-// Do we need them (STL doesn't make containers explicit)
-template<class G> concept bool Graph =  // general graph operations
-	requires { typename G::value_type; };
-template<class G> concept bool DAG = Graph<G> && requires(G g) { tops(g); };	 // operations simplified for DAGs 
-template<class G> concept bool Tree = DAG<G> && requires(G g) { top(g); };	 // operations simplified for trees
-
-// accessor concepts (like STL Iterators):
-template<class E> concept bool Edge_ref =      // most general and slowest
-	requires(E e) {
-  		typename E::value_type;
-  		{ *e } -> typename E::value_type;
-  		{ e.vertex } -> Vertex_ref;
-	};
-template<class E> concept bool DAG_edge_ref = // operations simplified for DAGs (any extra operations?)
-	Edge_ref<E> && false;	 
-template<class E> concept bool Tree_edge_ref = // operations simplified for trees (any extra operations?)
-	DAG_edge_ref<E> && false; 
-
-template<class V> concept bool Vertex_ref =       // most general and slowest
-  requires(V v, int i) {
-  		typename V::value_type;
-  		{ *v } -> typename V::value_type;
-  		{ v.edge[i] } -> Edge_ref;
-	};
-template<class V> concept bool DAG_vertex_ref = false;  // operations simplified for DAGs (any extra operations?)
-template<class V> concept bool Tree_vertex_ref = false; // operations simplified for DAGs (any extra operations?)
-
-// the value type (in a more general design, this would be a template parmeter):
-struct Val {};
-
-// specific directed graphs (note: we can't assume common structure or common naming from implementation):
-struct Tree {
-  	using value_type = Val;
-};
-
-struct Node_ref {};
-struct Edge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-void tops(Tree&);	// return vector Tree_vertex_refs
-Node_ref top(Tree&);
-
-struct Dag {
-  	using value_type = Val;
-};
-
-struct DAG_vertex_ref {};
-struct DAG_edge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-void tops(Dag&);
-
-struct Dgraph {
-  	using value_type = Val;
-};
-
-
-struct Gnode_ref {};
-struct Gedge_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-// another Graph representation:
-struct DGN_ref {};
-struct DGE_ref {};	// Is an Edge an object? (if not, refer to parent node)
-
-// use:
-#include <vector>
-using namespace std;
-
-template<Graph G, Vertex_ref R>
-void traverse(G& g, R r)
-{
-	vector<typename G::value_type> found;	// member g::value_type (old habit: could just have used Val)
-  	// ... 
-}
-
-void use1(Tree& t, Dag& d, Dgraph& dg, Node_ref& tr, DAG_vertex_ref& dr, Gnode_ref& gr)
-{
-  traverse(t,tr);
-  traverse(d,dr);
-  traverse(dg,gr);
-}