code: def imax(*args):
      """Evaluates the maximum of a list of intervals"""
      np = import_module("numpy")
      if not all(
          isinstance(arg, (int, float, interval)) for arg in args
      ):
          return NotImplementedError
      else:
          new_args = [
              a
              for a in args
              if isinstance(a, (int, float)) or a.is_valid
          ]
          if len(new_args) == 0:
              if all(a.is_valid is False for a in args):
                  return interval(-np.inf, np.inf, is_valid=False)
              else:
                  return interval(-np.inf, np.inf, is_valid=None)
          start_array = [
              a if isinstance(a, (int, float)) else a.start
              for a in new_args
          ]
  
          end_array = [
              a if isinstance(a, (int, float)) else a.end
              for a in new_args
          ]
  
          return interval(max(start_array), max(end_array))
  
imports: from functools import reduce
  from sympy.plotting.intervalmath import interval
  from sympy.external import import_module
label_desc: Use image node_id 11 for calling a global function with example usage: imax() and returns: NotImplementedError, interval, interval, interval