anchor.diff:    subroutine SXPDOT(Ndeg,Bi,B,Zln,Colno,Ks,Ke)
       implicit none
       !------
  -    integer, intent(IN):: Ke
  -    integer, intent(IN):: Ks
  -    integer, intent(IN):: Ndeg
  -    integer, intent(IN):: Colno(*)
  -    real(KIND=8), intent(IN):: Zln(Ndeg,Ndeg,*)
  -    real(KIND=8), intent(IN):: B(Ndeg,*)
  -    real(KIND=8), intent(OUT):: Bi(Ndeg)
  +    integer, intent(in):: Ke
  +    integer, intent(in):: Ks
  +    integer, intent(in):: Ndeg
  +    integer, intent(in):: Colno(*)
  +    real(kind=8), intent(in):: Zln(Ndeg,Ndeg,*)
  +    real(kind=8), intent(in):: B(Ndeg,*)
  +    real(kind=8), intent(out):: Bi(Ndeg)
       !------
       integer:: j
       integer:: jj
  
positive.code:     integer:: ke
      integer:: ks
      integer:: l
      real(KIND=8):: s(9)
  
      ks = Xlnzr(Ic)
      ke = Xlnzr(Ic+1)
  
negative.code:   subroutine NUFCT6(Xlnzr,Colno,Dsln,Zln,Diag,Indx,Temp,Neqns,Parent,Nch,Nstop,Ir)
      implicit none
      !------
      integer, intent(in):: Neqns
      integer, intent(in):: Nstop
      integer, intent(in):: Xlnzr(*)
      integer, intent(in):: Colno(*)
      integer, intent(in):: Parent(*)
      integer, intent(out):: Indx(*)
      integer, intent(out):: Nch(*)
      real(kind=8), intent(out):: Zln(36,*)
      real(kind=8), intent(out):: Diag(21,*)
      real(kind=8), intent(out):: Temp(*)
      real(kind=8), intent(out):: Dsln(36,*)
      !------
      integer:: ic
      integer:: Ir
      integer:: l
      real(kind=8):: t1
      real(kind=8):: t2
      real(kind=8):: t3
      real(kind=8):: t4
      real(kind=8):: t5
      real(kind=8):: tt
  
      !
      ! phase I
  