anchor.diff:    ! integer,  dimension(2,9)  :: elem
     integer, dimension(1, 16) :: elem
   
  -!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  -!!!!!!! Bi-linear quads !!!!!!!
  -!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  +! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  +! !!!!!! Bi-linear quads !!!!!!!
  +! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     ! Element connection(s) for 3 bi-linear quadrilaterals
     ! elem(1,:) = [1, 2, 3, 4]
     ! elem(2,:) = [2, 5, 6, 3]
  
positive.code:   ! xy(:,2) = [-1._wp, -2._wp, 5._wp, 3._wp]
    ! xy(:,1) = [0._wp, 0.03333_wp, 0.03333_wp, 0._wp]
    ! xy(:,2) = [0._wp, 0._wp, 0.03333_wp, 0.03333_wp]
  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  !!!!!!! Bi-linear quads !!!!!!!
  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  
  
  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  !!!!!!! Bi-quadratic quads !!!!!!!
  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    ! Element connection(s) for 2 bi-quadratic quadrilaterals
    ! elem(1,:) = [1, 2, 5, 6, 7, 8, 9, 10, 11]
    ! elem(2,:) = [2, 3, 4, 5, 12, 13, 14, 8, 15]
  
negative.code:   ! xy(1,:) = [-1.25_wp, -0.8_wp]
    ! xy(6,:) = [0.75_wp, 0.1_wp]
    ! xy(9,:) = [-0.25_wp, 0.25_wp]
  ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  ! !!!!!! Bi-cubic quads !!!!!!!
  ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  
    GlobalA = 0._wp
    do ii = 1, size(elem, 1)
  