diff --git a/graph/graph.h b/graph/graph.h
index f4e6ad7..ed81c23 100644
--- a/graph/graph.h
+++ b/graph/graph.h
@@ -12,13 +12,19 @@ class Graph {
 public:
   ~Graph();
 
-  // Add edge between v and u
-  virtual void insert(const T& v, const T& u);
+  // Add edge e(u,v)
+  virtual void insert(const T& u, const T& v);
 
-  // Number of vertices
+  // Return true if e(u,v) exists
+  virtual bool contains(const T& u, const T& v);
+
+  // Remove edge e(u,v)
+  virtual void remove(const T& u, const T& v);
+
+  // Return num. of vertices
   virtual std::uint16_t V();
 
-  // Number of edges
+  // Return num. of edges
   virtual std::uint16_t E();
 
   // Output graph
@@ -36,10 +42,20 @@ Graph<T>::~Graph() {
 }
 
 template<typename T>
-inline void Graph<T>::insert(const T& v, const T& u) {
-  Graph<T>::vertices.insert(v);
+inline void Graph<T>::insert(const T& u, const T& v) {
   Graph<T>::vertices.insert(u);
-  Graph<T>::adjMatrix[v].insert(u);
+  Graph<T>::vertices.insert(v);
+  Graph<T>::adjMatrix[u].insert(v);
+}
+
+template<typename T>
+bool Graph<T>::contains(const T& u, const T& v) {
+  return adjMatrix[u].contains(v);
+}
+
+template<typename T>
+void Graph<T>::remove(const T& u, const T& v) {
+  adjMatrix[u].erase(v);
 }
 
 template<typename T>