* `type` and `is` from [user defined value type definitions](https://docs.soliditylang.org/en/latest/grammar.html#a4.SolidityParser.userDefinedValueTypeDefinition). * `from` and `as` from [import directives](https://docs.soliditylang.org/en/latest/grammar.html#a4.SolidityParser.importDirective)
