double complex function A51ppppp(j1,j2,j3,j4,j5,za,zb)
      implicit none
      include 'constants.f'
      include 'sprods_com.f'
      include 'zprods_decl.f'
      integer j1,j2,j3,j4,j5
      double complex asym,sym
      asym=+zb(j1,j2)*za(j2,j3)*zb(j3,j4)*za(j4,j1)
     &     -za(j1,j2)*zb(j2,j3)*za(j3,j4)*zb(j4,j1)
      sym=dcmplx(s(j1,j2)*s(j2,j3)+s(j2,j3)*s(j3,j4)
     &          +s(j3,j4)*s(j4,j5)+s(j4,j5)*s(j5,j1)+s(j5,j1)*s(j1,j2))

C----Eq.(4) of hep-ph/9302280v1 of BDK multiplied by 16*pi^2*(-i)*(-1)
C--- to give (16*pi^2)*(-i)*A^{[1/2]}_{5;1}
      A51ppppp=-(sym+asym)
     % /(6d0*za(j1,j2)*za(j2,j3)*za(j3,j4)*za(j4,j5)*za(j5,j1))
      return
      end