old_contents: import numpy as nm
  from linear_elastic import \
       filename_mesh, materials, regions, fields, ebcs, \
       integrals, solvers, fe
  
  options = {
      'ts' : 'ts',
      'save_steps' : -1,
  }
  
  variables = {
      'u' : ('unknown field', 'displacement', 0, 'previous'),
      'v' : ('test field', 'displacement', 'u'),
  }
  
  # Put density to 'solid'.
  materials['solid'][0].update({'rho' : 1000.0})
  
  # Moving the PerturbedSurface region.
  ebcs['PerturbedSurface'][1].update({'u.0' : 'ebc_sin'})
  
  def ebc_sin(ts, coors, bc=None):
      val = 0.01 * nm.sin(2.0*nm.pi*ts.nt)
      return nm.tile(val, (coors.shape[0],))
  
  functions = {
      'ebc_sin' : (ebc_sin,),
  }
  
  equations = {
      'balance_of_forces in time' :
      """dw_mass_vector.i1.Omega( solid.rho, v, du/dt )
       + dw_lin_elastic_iso.i1.Omega( solid.lam, solid.mu, v, u ) = 0""",
  }
  
  solvers.update({
      'ts' : ('ts.simple',
              {'t0' : 0.0,
               't1' : 1.0,
               'dt' : None,
               'n_step' : 101
               }),
  })
  
  # Pre-assemble and factorize the matrix prior to time-stepping.
  newton = solvers['newton']
  newton[1].update({'problem' : 'linear'})
  
  ls = solvers['ls']
  ls[1].update({'presolve' : True})
  
new_contents: import numpy as nm
  from linear_elastic import \
       filename_mesh, materials, regions, fields, ebcs, \
       integrals, solvers
  
  options = {
      'ts' : 'ts',
      'save_steps' : -1,
  }
  
  variables = {
      'u' : ('unknown field', 'displacement', 0, 'previous'),
      'v' : ('test field', 'displacement', 'u'),
  }
  
  # Put density to 'solid'.
  materials['solid'][0].update({'rho' : 1000.0})
  
  # Moving the PerturbedSurface region.
  ebcs['PerturbedSurface'][1].update({'u.0' : 'ebc_sin'})
  
  def ebc_sin(ts, coors, bc=None):
      val = 0.01 * nm.sin(2.0*nm.pi*ts.nt)
      return nm.tile(val, (coors.shape[0],))
  
  functions = {
      'ebc_sin' : (ebc_sin,),
  }
  
  equations = {
      'balance_of_forces in time' :
      """dw_mass_vector.i1.Omega( solid.rho, v, du/dt )
       + dw_lin_elastic_iso.i1.Omega( solid.lam, solid.mu, v, u ) = 0""",
  }
  
  solvers.update({
      'ts' : ('ts.simple',
              {'t0' : 0.0,
               't1' : 1.0,
               'dt' : None,
               'n_step' : 101
               }),
  })
  
  # Pre-assemble and factorize the matrix prior to time-stepping.
  newton = solvers['newton']
  newton[1].update({'problem' : 'linear'})
  
  ls = solvers['ls']
  ls[1].update({'presolve' : True})
  
subject: fix example for removed "fe" keyword