parameters: (value_string)
return_statement: return True
docstring: Returns true iff 'value_string' is a value_string
      of an implicit feature.
docstring_summary: Returns true iff 'value_string' is a value_string
      of an implicit feature.
docstring_tokens: Returns true iff value_string is a value_string of an implicit feature .
function: def is_implicit_value (value_string):
      """ Returns true iff 'value_string' is a value_string
      of an implicit feature.
      """
      assert isinstance(value_string, basestring)
      if value_string in __implicit_features:
          return __implicit_features[value_string]
  
      v = value_string.split('-')
  
      if v[0] not in __implicit_features:
          return False
  
      feature = __implicit_features[v[0]]
  
      for subvalue in (v[1:]):
          if not __find_implied_subfeature(feature, subvalue, v[0]):
              return False
  
      return True
function_tokens: def is_implicit_value ( value_string ) : assert isinstance ( value_string , basestring ) if value_string in __implicit_features : return __implicit_features [ value_string ] v = value_string . split ( '-' ) if v [ 0 ] not in __implicit_features : return False feature = __implicit_features [ v [ 0 ] ] for subvalue in ( v [ 1 : ] ) : if not __find_implied_subfeature ( feature , subvalue , v [ 0 ] ) : return False return True