{\scriptsize
\begin{verbatim}
     ...    ...
      |      )
      |      (---- CALL OPTLINE / LSLINE
      |      )       |
      |      (       |---- /// loop over simulations
      |      )              (  
      |      (              )---- CALL SIMUL
      |      )              (       |
      |      (              )       |----  input: xdiff(i)
      |      )              (       |---- output: ff(i), gg(i)
      |      (              )       |---- >>> if ONLINE <<<
      |      )              (                 runs model and adjoint
      |      (              )             >>> if OFFLINE <<<
      |      )              (                 reads those values from file
      |      (              )
      |      )              (---- 1st Wolfe test:
      |      (              )     ff(i) <= tact*xpara1*<gg(i-1),dd(i-1)>
      |      )              (
      |      (              )---- 2nd Wolfe test:
      |      )              (     <gg(i),dd(i-1)> >= xpara2*<gg(i-1),dd(i-1)>
      |      (              )
      |      )              (---- >>> if 1st and 2nd Wolfe tests ok <<<
      |      (              )      |  320: update xx: xx(i) = xdiff(i)
      |      )              (      |
      |      (              )     >>> else if 1st Wolfe test not ok <<<
      |      )              (      |  500: INTERpolate new tact:
      |      (              )      |  barr*tact < tact < (1-barr)*tact
      |      )              (      |  CALL CUBIC
      |      (              )      |
      |      )              (     >>> else if 2nd Wolfe test not ok <<<
      |      (              )         350: EXTRApolate new tact:
      |      )              (         (1+barmin)*tact < tact < 10*tact
      |      (              )         CALL CUBIC
      |      )              (
      |      (              )---- >>> if new tact > tmax <<<
      |      )              (      |  ifail = 7
      |      (              )      |
      |      )              (---- >>> if new tact < tmin OR tact*dd < machine precision <<<
      |      (              )      |  ifail = 8
      |      )              (      |
      |      (              )---- >>> else <<<
      |      )              (         update xdiff for new simulation
      |      (              )
      |      )             \\\ if nfunc > 1: use inter-/extrapolated tact and xdiff
      |      (                               for new simulation
      |      )                               N.B.: new xx is thus not based on new gg, but
      |      (                                     rather on new step size tact
      |      )        
      |      (---- store new values xx(i), gg(i) to OPWARMD (first 2 entries)
      |      )---- >>> if ifail = 7,8,9 <<<
      |      (         goto 1000
      |      )
     ...    ...
\end{verbatim}
}