old_contents: import argparse
  
  
  from lenrmc.nubase import System
  
  
  class App(object):
  
      def __init__(self, **kwargs):
          self.kwargs = kwargs
  
      def run(self):
          s = System.parse(self.kwargs['system'], **self.kwargs)
          for reaction in s.terminal():
              print(reaction)
  
  
  def parse_arguments():
      parser = argparse.ArgumentParser()
      parser.add_argument('system', type=str)
      parser.add_argument('--lb', dest='lower_bound', help='lower bound in keV')
      parser.set_defaults(lower_bound=-1000)
      return parser.parse_args()
  
  
  if '__main__' == __name__:
      opts = parse_arguments()
      App(**vars(opts)).run()
  
new_contents: import argparse
  
  
  from lenrmc.nubase import System
  
  
  class App(object):
  
      def __init__(self, **kwargs):
          self.kwargs = kwargs
  
      def run(self):
          s = System.parse(self.kwargs['system'], **self.kwargs)
          for reaction in s.terminal():
              print(reaction)
  
  
  def parse_arguments():
      parser = argparse.ArgumentParser()
      parser.add_argument('system', type=str)
      parser.add_argument('--lb', dest='lower_bound', help='lower bound in keV')
      parser.set_defaults(lower_bound=0)
      return parser.parse_args()
  
  
  if '__main__' == __name__:
      opts = parse_arguments()
      App(**vars(opts)).run()
  
subject: Change the default lower bound.