anchor.diff:        _wrapped._dumpState();
       }
       if (isQuery) {
  -      print('  => $result');
  +      print('  => ${_describe(result)}');
       }
       return result;
  +  }
  +
  +  static String _describe(Object? value) {
  +    if (value != null && value is! String && value is! num && value is! bool) {
  +      String? description = _description[value];
  +      if (description != null) return description;
  +    }
  +    return value.toString();
     }
   }
   
  
positive.code:   }
  
    @override
    VariableModel<Variable, Type>? _getInfo(
        Map<Variable?, VariableModel<Variable, Type>> variableInfo) {
      VariableModel<Variable, Type> targetInfo = target.getInfo(variableInfo);
  
negative.code:   final Type type;
  
    ReferenceWithType(this.reference, this.type);
  
    @override
    String toString() => 'ReferenceWithType($reference, $type)';
  }
  
  /// Data structure representing a unique value that a variable might take on
  