anchor.diff:  c...  loop over number of slippery node entries to find slippery nodes
   c     on each fault
   c
  -      iflip=0
  -      isp=0
  -      ii=0
  +      iflip=izero
  +      isp=izero
  +      ii=izero
         call ifill(itmp1,izero,numsn)
         call ifill(itmp2,izero,numsn)
         do n=1,numslp
           nelem=nslip(1,n)
           node=nslip(2,n)
           do i=1,ndof
  -          if(nslip(2+i,n).ne.0) isn=nslip(2+i,n)
  +          if(nslip(2+i,n).ne.izero) isn=nslip(2+i,n)
           end do
           if(isn.eq.-isp) iflip=iflip+1
           nssurf=1+iflip/2
  
positive.code:       end
  c
  c version
  c $Id: nfind.f,v 1.1 2004/04/14 21:18:30 willic3 Exp $
  c
  c Generated automatically by Fortran77Mill on Wed May 21 14:15:03 2003
  c
  
negative.code: 10      continue
        end do
        call ifill(ipslp,izero,npdim*numsn)
        iadd=izero
        do nn=1,nssurf
          do n=1,itmp2(nn)
            node=itmp1(n+iadd)
  