Interface inheritance

How do we show in code that an interface inherits from another interface?

interface MyInterface {}

//====== [1] ======
interface MyDerivedInterface from MyInterface {
    /* ... */
}

//====== [2] ======
interface MyDerivedInterface : MyInterface {
    /* ... */
}

//====== [3] ======
interface MyDerivedInterface::MyInterface {
    /* ... */
}

//====== [4] ======
interface MyDerivedInterface -> MyInterface {
    /* ... */
}