diff --git a/EGkCurveComposite.h b/EGkCurveComposite.h
index 15bbba7..4d7970c 100644
--- a/EGkCurveComposite.h
+++ b/EGkCurveComposite.h
@@ -20,6 +20,9 @@
 //----------------------------------------------------------------------------
 class __declspec( novtable) ICurveComposite : public ICurve
 {
+   public :
+      enum  DeletedCurve { NONE = 0, PREV = 1, NEXT = 2 } ;
+
    public :                      // IGeoObj
       ICurveComposite* Clone( void) const override = 0 ;
    public :
@@ -49,7 +52,8 @@ class __declspec( novtable) ICurveComposite : public ICurve
       virtual bool AddArc2P( const Point3d& ptOther, const Point3d& ptNew, bool bEndOrStart = true) = 0 ;
       virtual bool AddArcTg( const Point3d& ptNew, bool bEndOrStart = true) = 0 ;
       virtual bool AddJoint( double dU) = 0 ;
-      virtual bool ModifyJoint( int nU, const Point3d& ptNewJoint) = 0 ;
+      virtual bool ModifyJoint( int nU, const Point3d& ptNewJoint, int* pnFlagDel = nullptr) = 0 ;
+      virtual bool ModifyJoint( int nU, const Point3d& ptNewJoint, double dTol) = 0 ;
       virtual bool RemoveJoint( int nU) = 0 ;
       virtual bool MoveCurve( int nCrv, const Vector3d& vtMove) = 0 ;
       virtual bool ModifyCurveToArc( int nCrv, const Point3d& ptMid) = 0 ;
@@ -71,6 +75,7 @@ class __declspec( novtable) ICurveComposite : public ICurve
       virtual bool SetCurveTempParam( int nCrv, double dParam, int nParamInd = 0) = 0 ;
       virtual bool GetCurveTempParam( int nCrv, double& dParam, int nParamInd = 0) const = 0 ;
       virtual bool GetOnlyPoint( Point3d& ptStart) const = 0 ;
+      virtual bool ModifySingleCurve( int nSubCrv, ICurve* pNewCurve, double dTolStartEnd, double dTolAlong = INFINITO) = 0 ;
 } ;
 
 //-----------------------------------------------------------------------------