anchor.diff:  
         end do
   
  -      return
   end subroutine blockdis
   
   subroutine chroma
  
positive.code:       use mod_common_track
        implicit none
        integer i,j,jm,k,l,m,n
        real(kind=fPrec) aeg,bl1eg,bl2eg,g,h
        dimension h(nblo,2,6),g(nblo,2,6)
        dimension aeg(nele,2,6),bl1eg(nblo,2,6),bl2eg(nblo,2,6)
        save
  !-----------------------------------------------------------------------
        do k=1,mblo
          jm=mel(k)
          i=mtyp(k,1)
  
negative.code:       use mod_common_track
        implicit none
        integer i,j,jm,k,l,m,n
        real(kind=fPrec) h(nblo,2,6),g(nblo,2,6)
  
        do k=1,mblo
          jm=mel(k)
          i=mtyp(k,1)
  