diff --git a/LibAutomaton/matrix.c b/LibAutomaton/matrix.c
index 40893f1..ed0b051 100644
--- a/LibAutomaton/matrix.c
+++ b/LibAutomaton/matrix.c
@@ -299,7 +299,7 @@ Matrix freeMatrix(Matrix matrix){
 
 	matrix.colCount = 0;
 	matrix.rowCount = 0;
-	/*il faut free les cellElements car FreeList ne peut pas le faire*/
+
 	if (matrix.cols != NULL){
 		current= matrix.cols->head;
 		while (current != NULL){
@@ -312,6 +312,29 @@ Matrix freeMatrix(Matrix matrix){
 	return matrix;
 }
 
+Matrix sumMatrix(Matrix matrix1,Matrix matrix2){
+	Matrix SumMatrix = CreateMatrix();
+	int i =0;
+	int j = 0;
+
+	if (matrix1.colCount == matrix2.colCount && matrix1.rowCount == matrix2.rowCount){
+		SumMatrix = SetMatrixDim(SumMatrix,matrix2.colCount,matrix1.rowCount);
+		for (i=0;i<SumMatrix.colCount;i++){
+			for (j=0;j<SumMatrix.rowCount;j++){
+				SetCellValue(SumMatrix,i,j,GetCellValue(matrix1,i,j)+GetCellValue(matrix2,i,j));
+				
+				}
+		}
+	}else{
+		printf("\n- error : Matrices haven't the same size -\n");
+		
+		SumMatrix.colCount = -1;
+		SumMatrix.rowCount = -1;
+	}
+	
+	return SumMatrix;
+	
+}
 
 Matrix colSequenceOnMatrix(Matrix m, bool (operator)(bool, bool)){
 	bool a;
@@ -383,7 +406,8 @@ Matrix orRowSequenceOnMatrix(Matrix m){
 }
 
 /* todos :
-*finir le freeMatrix
+*mulMatrix
+*
 *chasser les bugs
 *ecrire doc
 *faire un print + opti pour que sli l'adapte avec sdl
diff --git a/LibAutomaton/matrix.h b/LibAutomaton/matrix.h
index 289fa70..2f8f87a 100644
--- a/LibAutomaton/matrix.h
+++ b/LibAutomaton/matrix.h
@@ -186,6 +186,8 @@ Matrix andRowSequenceOnMatrix(Matrix m);
 * @return matrix the copmuted matrix
 */
 Matrix orRowSequenceOnMatrix(Matrix m);
+Matrix sumMatrix(Matrix matrix1,Matrix matrix2);
+
 
 #endif