BezierInfo-2/docs/images/snippets/extremities/bf0ad4611c47f8548396e40595c02b55.ascii

 
B(t)  uses { p ,p ,p ,p  }                                                  
              1  2  3  4                                                    
B'(t)  uses { v ,v ,v  },  where v  = 3(p -p ), v  = 3(p -p ), v  = 3(p -p )
               1  2  3            1      2  1    2      3  2    3      4  3