anchor.diff:        if (info .ne. 0) then
   c          nonpositive definiteness in Cholesky factorization;
   c          refresh the lbfgs memory and restart the iteration.
  -         if(iprint .ge. 1) write (6, 1006)
  +         if(iprint .ge. 1) write (0, 1006)
            info   = 0
            col    = 0
            head   = 1
  
positive.code:             goto 999
           else
  c             refresh the lbfgs memory and restart the iteration.
              if(iprint .ge. 1) write (6, 1008)
              if (info .eq. 0) nfgv = nfgv - 1
              info   = 0
              col    = 0
  
negative.code:      +            iprint, sbgnrm, info, epsmch)
        if (info .ne. 0) then 
  c         singular triangular system detected; refresh the lbfgs memory.
           if(iprint .ge. 1) write (0, 1005)
           info   = 0
           col    = 0
           head   = 1
  