anchor.diff:       & bintern,neq,                                                     ! force
        & x,d,deld,numnp,                                                  ! global
        & s,stemp,                                                         ! stiff
  -     & dmat,ien,lm,lmx,infiel,iddmat,ndmatsz,numelt,nconsz,             ! elemnt
  -     & infmat,infmatmod,numat,                                          ! materl
  -     & gauss,sh,shj,infetype,                                           ! eltype
  +     & dmat,ien,lm,lmx,ivfamily,nvfamilies,numelv,                      ! elemnt
  +     & infmatmod,                                                       ! materl
  +     & gauss,sh,shj,nen,ngauss,nee,                                     ! eltype
        & skew,numrot,                                                     ! skew
        & getshape,bmatrix,                                                ! bbar
        & ierr,errstrng)                                                   ! errcode
  
positive.code: c
  c...  form element stiffness matrix
  c
            inddmat=infiel(6,iel)
            ngauss=infetype(1,ietype)
            nee=infetype(4,ietype)
            ngaussdim=max(ngauss,ngtest)
  c
            call formes_ss(
       &     x,numnp,                                                     ! global
       &     s,stemp,                                                     ! stiff
       &     dmat(1,inddmat),ien(indien),lm(1,indien),iddmat,iel,         ! elemnt
       &     gauss(1,1,ietype),sh(1,1,1,ietype),shj(1,1,1,ietype),        ! eltype
       &     ngauss,ngaussdim,nen,nee,                                    ! eltype
       &     skew,numrot,                                                 ! skew
       &     getshape,bmatrix,                                            ! bbar
       &     ierr,errstrng)                                               ! errcode
  
negative.code: c
  c...  local variables
  c
        integer ifam,nelfamily,matmodel,ielf,ielg,i
        double precision p(60),dld(60)
  cdebug      integer idb
  c
  cdebug      write(6,*) "Hello from formdf_ss_f!"
  c
        ielg=izero
  c
  c...  loop over element families
  c
        do ifam=1,nvfamilies
          nelfamily=ivfamily(1,ifam)
          matmodel=ivfamily(2,ifam)
          do ielf=1,nelfamily
            ielg=ielg+ione
  c
  c...  localize displacement BC
  c
            call ldisbc(dld,deld,ien(1,ielg),lm(1,ielg),nen,numnp)
            do i=1,ndof*nen
              if(dld(i).ne.zero) go to 100
            end do
  