anchor.diff:  c...for first iteration, update displacements to reflect boundary
   c   conditions
   c
  -        if(iter.eq.1) then
  +        if(iter.eq.1.and.iprestress.eq.0) then
             if(numfn.ne.0.and.numrot.ne.0) call rsplit(nfault,dfault,
        &     skew,numfn,numnp)
             if(numfn.ne.0) call daxpy(ndof*numfn,one,dfault,ione,tfault,
  
positive.code: c
  c...  subroutine arguments
  c
        integer ierr
        integer ja(*)
        integer id(*),iwink(*)
        integer idx(*),iwinkx(*),idslp(*),ipslp(*)
  
negative.code:           if(numslp.ne.0) call rdisp(dxcur,skew,numnp)
          end if
  c
  c...  zero internal force vector prior to recomputing it.
  c
          call fill(bintern,zero,neq)
  c
  