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  * All the software  contained in this library is protected by *
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  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS*
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   AUTHORS:
       G. Casciola, L. Romani
       Dept. of Mathematics 
       University of Bologna, Italy
       e-mail: {casciola,romani}@dm.unibo.it

       E. Franchini
       Dept. of Pure and Applied Mathematics
       University of Padova, Italy
       e-mail: elena.franchini@inwind.it

   REFERENCE:
      The mixed directional difference-summation algorithm for 
      generating the Bzier net of a trivariate four-direction 
      Box-spline, G. Casciola, E. Franchini, L. Romani.
      Numerical Algorithms, 43 (2006), pp. 75-98   

   SOFTWARE REVISION DATE:
       March 2006

   SOFTWARE LANGUAGE:
       Matlab 7.X
