Extending vs. implementing a pure abstract class in TypeScript

Question

Suppose I have a pure abstract class (that is, an abstract class without any implementation):

abstract class A {
    abstract m(): void;
}

Answer 1

In the example of extends that you give you don't actually add anything new to the class. So it is extended by nothing. Although extending by nothing is valid Typescript it would seem to me that in this case 'implements' would be more appropriate. But at the end of the day they are equivalent.