Qwertiy

@sandersn why do you compare abstract class C { p?: number } abstract class C { abstract p?: number } they are already different. But abstract class C { abstract...

@sandersn I don't understand you still. [Here is code for TS3](https://www.typescriptlang.org/play?ts=3.9.7#code/IYIwzgLgTsDGEAJYBthjAgggg3gKAUIQAcoB7CAU3koBMEpLhayA7ZATwTAFsIALAPwAuBKwCuPEJSh4CRYuJDIAlrAQAzABQBKXPKJFYbMGWSUAdMjIBzLQJVgLvAToMIAvni94UaDABCCJQAHlSstBjY+IYu-AgAvAgAjAAM3nJ+6AgAwsFhlBFR+oY2lIhxurgM5eJQrAgAssACFjARZDxVXj5ZGAAi+eGRWPo+rJQA7ggBuhbabhPTOXMLeEsI-au6QA) - how do you propose to update class `A` without changing `B`, `C` and `D` so that the code...

@sandersn I want optional field and all 3 classes compatible with `A`. For me it seems impossible now, isn't it?