diff --git a/eo/test/t-eoExtendedVelocity.cpp b/eo/test/t-eoExtendedVelocity.cpp
index c019bf69..d40d2881 100644
--- a/eo/test/t-eoExtendedVelocity.cpp
+++ b/eo/test/t-eoExtendedVelocity.cpp
@@ -43,20 +43,20 @@ int main_function(int argc, char **argv)
     eoExtendedVelocity <Particle> velocity (topology,1,1,1,1);
     
     // the test itself
-    for (unsigned int i = 0; i < POP_SIZE; ++i)
+    for (unsigned int i = 0; i < POP_SIZE; i++)
     {
       std::cout << " Initial particle n°" << i << " velocity: " <<  std::endl;
-      for (unsigned int j = 0; j < VEC_SIZE; ++j)
+      for (unsigned int j = 0; j < VEC_SIZE; j++)
     		std::cout << " v" << j << "=" << pop[i].velocities[j] << std::endl;    
     }
     
-    for (unsigned int i = 0; i < POP_SIZE; ++i)
+    for (unsigned int i = 0; i < POP_SIZE; i++)
    	 velocity (pop[i],i);
    	 
-   	for (unsigned int i = 0; i < POP_SIZE; ++i)
+   	for (unsigned int i = 0; i < POP_SIZE; i++)
     {
       std::cout << " Final particle n°" << i << " velocity: " <<  std::endl;
-      for (unsigned int j = 0; j < VEC_SIZE; ++j)
+      for (unsigned int j = 0; j < VEC_SIZE; j++)
     		std::cout << " v" << j << "=" << pop[i].velocities[j] << std::endl;    
     }
 	
diff --git a/eo/test/t-eoOrderXover.cpp b/eo/test/t-eoOrderXover.cpp
index 1280cf84..f44b8c69 100644
--- a/eo/test/t-eoOrderXover.cpp
+++ b/eo/test/t-eoOrderXover.cpp
@@ -2,11 +2,12 @@
 // t-eoOrderXover.cpp
 //-----------------------------------------------------------------------------
 
-#include <eo>
+#include <set>
 
+#include <eo>
 #include <eoInt.h>
 #include <eoOrderXover.h>
-#include <set>
+
 
 //-----------------------------------------------------------------------------
 
@@ -56,13 +57,13 @@ int main()
   eoOrderXover<Chrom> cross;
   
   for (i = 0; i < POP_SIZE; ++i)
-    std::cout << " Initial chromosome n°" << i << " : " << pop[i] << "..." <<  std::endl;
+    std::cout << " Initial chromosome n�" << i << " : " << pop[i] << "..." <<  std::endl;
 
   cross(pop[0],pop[1]);
   cross(pop[1],pop[2]);
       
    for (i = 0; i < POP_SIZE; ++i) {
-	std::cout << " Initial chromosome n°" << i << " becomes : " << pop[i] << " after orderXover" << std::endl;	
+	std::cout << " Initial chromosome n�" << i << " becomes : " << pop[i] << " after orderXover" << std::endl;	
 	check_permutation(pop[i]);
    }
   return 0;
diff --git a/eo/test/t-eoSwapMutation.cpp b/eo/test/t-eoSwapMutation.cpp
index af35b42f..f2c33789 100644
--- a/eo/test/t-eoSwapMutation.cpp
+++ b/eo/test/t-eoSwapMutation.cpp
@@ -2,8 +2,9 @@
 // t-eoSwapMutation.cpp
 //-----------------------------------------------------------------------------
 
-#include <eo>
+#include <set>
 
+#include <eo>
 #include <eoInt.h>
 #include <eoSwapMutation.h>
 
@@ -22,20 +23,21 @@ double real_value(const Chrom & _chrom)
   return sum/_chrom.size();
 }
 
+//-----------------------------------------------------------------------------
 // Return true if the given chromosome corresponds to a permutation
-// There must be an nicer way to do it (set?) ...
-bool check_permutation(const Chrom & _chrom)
-{
-	for (unsigned i = 0; i < _chrom.size(); ++i)
-		for (unsigned j = 0; j < _chrom.size(); ++j)
-			if(i!=j)
-				if(_chrom[i]==_chrom[j]){
-						 std::cout << " Error: Wrong permutation !" << std::endl;
-						 std::string s;
-						 s.append( " Wrong permutation in t-eoSwapMutation");
-	    				 throw std::runtime_error( s );	
-				}
-	return true;				
+bool check_permutation(const Chrom& _chrom){
+	unsigned size= _chrom.size();
+	std::set<unsigned> verif;
+	for(unsigned i=0; i< size; i++){
+		if(verif.insert(_chrom[i]).second==false){
+			std::cout << " Error: Wrong permutation !" << std::endl;
+			std::string s;
+			s.append( " Wrong permutation in t-eoShiftMutation");
+			throw std::runtime_error( s );
+			return false;
+		}
+	}
+	return true;
 }
 
 
diff --git a/eo/test/t-eoTwoOptMutation.cpp b/eo/test/t-eoTwoOptMutation.cpp
index bfc68fe6..95e713a6 100644
--- a/eo/test/t-eoTwoOptMutation.cpp
+++ b/eo/test/t-eoTwoOptMutation.cpp
@@ -2,8 +2,9 @@
 // t-eoTwoOptMutation.cpp
 //-----------------------------------------------------------------------------
 
-#include <eo>
+#include <set>
 
+#include <eo>
 #include <eoInt.h>
 #include <eoTwoOptMutation.h>
 
@@ -22,20 +23,21 @@ double real_value(const Chrom & _chrom)
   return sum/_chrom.size();
 }
 
+//-----------------------------------------------------------------------------
 // Return true if the given chromosome corresponds to a permutation
-// There must be an nicer way to do it (set?) ...
-bool check_permutation(const Chrom & _chrom)
-{
-	for (unsigned i = 0; i < _chrom.size(); ++i)
-		for (unsigned j = 0; j < _chrom.size(); ++j)
-			if(i!=j)
-				if(_chrom[i]==_chrom[j]){
-						 std::cout << " Error: Wrong permutation !" << std::endl;
-						 std::string s;
-						 s.append( " Wrong permutation in t-eoTwoOptMutation");
-	    				 throw std::runtime_error( s );	
-				}
-	return true;				
+bool check_permutation(const Chrom& _chrom){
+	unsigned size= _chrom.size();
+	std::set<unsigned> verif;
+	for(unsigned i=0; i< size; i++){
+		if(verif.insert(_chrom[i]).second==false){
+			std::cout << " Error: Wrong permutation !" << std::endl;
+			std::string s;
+			s.append( " Wrong permutation in t-eoShiftMutation");
+			throw std::runtime_error( s );
+			return false;
+		}
+	}
+	return true;
 }