diff --git a/cartailor.html b/cartailor.html
index a6b05a7..81b9d3a 100644
--- a/cartailor.html
+++ b/cartailor.html
@@ -13,26 +13,14 @@ th,td{border: 1px solid rgb(160 160 160);padding: 8px 10px;}</style>
 			<th>EG210</th>
 			<th>25000 €</th>
 		</tr>
-		<tr>
-			<th>Interior</th>
-			<th>IS</th>
-			<th>2500 €</th>
-			<th>color : red</th>
-		</tr>
 		<tr>
 			<th>Transmission</th>
 			<th>TSF7</th>
 			<th>15000 €</th>
 		</tr>
-		<tr>
-			<th>Exterior</th>
-			<th>XS</th>
-			<th>10000 €</th>
-			<th>color : red</th>
-		</tr>
 		<tr>
 			<th colspan="2">Total Price : </th>
-			<th>52500 € </th>
+			<th>40000 € </th>
 		</tr>
 	</table>
 </body>
diff --git a/src/fr/impl/ConfigurationImpl.java b/src/fr/impl/ConfigurationImpl.java
index f5775bd..0f9d244 100644
--- a/src/fr/impl/ConfigurationImpl.java
+++ b/src/fr/impl/ConfigurationImpl.java
@@ -26,7 +26,7 @@ public class ConfigurationImpl implements Configuration {
             for(String pr: pt1.getPropertyNames()){
                 Optional<String> prOptional = pt1.getProperty(pr);
                 if(!prOptional.isEmpty()){
-                    test = ((PartImpl)pt1).isValidProperty(pr);
+                    test = test && ((PartImpl)pt1).isValidProperty(pr);
                 }
                 else test = false;
             }
@@ -67,7 +67,9 @@ public class ConfigurationImpl implements Configuration {
             else System.out.println("\tnot ok");
             System.out.println(test_Requirement + " " + test_Incompabilities);
             test = test && test_Requirement && test_Incompabilities;
+            System.out.println("post final : " + test);
         }
+        System.out.println("final : " + test);
         return test;
     }
 
diff --git a/src/fr/impl/Parts/Engine.java b/src/fr/impl/Parts/Engine.java
index 5c384cf..25232f2 100644
--- a/src/fr/impl/Parts/Engine.java
+++ b/src/fr/impl/Parts/Engine.java
@@ -26,7 +26,10 @@ public class Engine extends PartImpl {
 
      @Override
      public void setType(PartType type){
-        this.type = type;
-        this.price = prices.get(type.getName());
+     this.type = type;
+     if(prices.containsKey(type.getName())){
+          this.price = prices.get(type.getName());
+     }
+     else this.price = 0;
     }
 }
diff --git a/src/fr/impl/Parts/Exterior.java b/src/fr/impl/Parts/Exterior.java
index bbe1b4c..3d6be30 100644
--- a/src/fr/impl/Parts/Exterior.java
+++ b/src/fr/impl/Parts/Exterior.java
@@ -47,7 +47,10 @@ public class Exterior extends PartImpl {
 
      @Override
      public void setType(PartType type){
-        this.type = type;
-        this.price = prices.get(type.getName());
+          this.type = type;
+          if(prices.containsKey(type.getName())){
+               this.price = prices.get(type.getName());
+          }
+          else this.price = 0;
     }
 }
diff --git a/src/fr/impl/Parts/Interior.java b/src/fr/impl/Parts/Interior.java
index 8a75f96..9b7d78d 100644
--- a/src/fr/impl/Parts/Interior.java
+++ b/src/fr/impl/Parts/Interior.java
@@ -47,8 +47,11 @@ public class Interior extends PartImpl {
 
      @Override
      public void setType(PartType type){
-        this.type = type;
-        this.price = prices.get(type.getName());
+          this.type = type;
+          if(prices.containsKey(type.getName())){
+               this.price = prices.get(type.getName());
+          }
+          else this.price = 0;
     }
 
 }
diff --git a/src/fr/impl/Parts/Transmission.java b/src/fr/impl/Parts/Transmission.java
index 28c3c96..b729251 100644
--- a/src/fr/impl/Parts/Transmission.java
+++ b/src/fr/impl/Parts/Transmission.java
@@ -26,7 +26,10 @@ public class Transmission extends PartImpl {
 
      @Override
      public void setType(PartType type){
-        this.type = type;
-        this.price = prices.get(type.getName());
+          this.type = type;
+          if(prices.containsKey(type.getName())){
+               this.price = prices.get(type.getName());
+          }
+          else this.price = 0;
     }
 }
diff --git a/src/fr/test/test_V1.java b/src/fr/test/test_V1.java
index 05602c1..61060a0 100644
--- a/src/fr/test/test_V1.java
+++ b/src/fr/test/test_V1.java
@@ -206,6 +206,28 @@ public class test_V1 {
         assertTrue(cm.getIncompatibilities(TSF7).contains(ED110));
     }
 
+    @Test
+    public void test_contradiction(){
+        CompatibilityManager cm2 = new CompatibilityManagerImpl();
+        PartType eg= new PartTypeImpl("eg",Engine.class, engine);
+        PartType tr= new PartTypeImpl("Tr", Transmission.class, transmission);
+
+        Set<PartType> egIncompatibilities = new HashSet<PartType>();
+        egIncompatibilities.add(tr);
+        cm.addIncompatibilities(eg, egIncompatibilities);
+
+        Set<PartType> efRequirement = new HashSet<PartType>();
+        efRequirement.add(eg);
+        cm.addRequirements(tr, efRequirement);
+
+
+        assertFalse(cm.getIncompatibilities(eg).contains(eg));
+        assertTrue(cm.getRequirements(tr).contains(eg));
+        assertTrue(cm.getIncompatibilities(tr).contains(tr)); //tr Require eg, eg Incompatible tr, -> eg Incompatible eg
+
+    }
+
+
 
     //Configuration
 
@@ -320,4 +342,29 @@ public class test_V1 {
         assertTrue(config1.isValid());
     }
 
+    @Test
+    public void test_contradiction_config(){
+        CompatibilityManager cm2 = new CompatibilityManagerImpl();
+        PartType eg= new PartTypeImpl("eg",Engine.class, engine);
+        PartType tr= new PartTypeImpl("Tr", Transmission.class, transmission);
+        PartType ex= new PartTypeImpl("Ex", Exterior.class, exterior);
+        PartType in= new PartTypeImpl("In", Interior.class, interior);
+
+        Set<PartType> egIncompatibilities = new HashSet<PartType>();
+        egIncompatibilities.add(tr);
+        cm2.addIncompatibilities(eg, egIncompatibilities);
+
+        Set<PartType> efRequirement = new HashSet<PartType>();
+        efRequirement.add(eg);
+        cm2.addRequirements(eg, efRequirement);
+
+        ConfigurationImpl config1 = new ConfigurationImpl(cm2);
+        config1.selectPart(eg);
+        config1.selectPart(tr);
+        config1.selectPart(ex);
+        config1.selectPart(in);
+
+        assertFalse(config1.isValid());
+    }
+
 }