Per this [link](https://stackoverflow.com/a/33866478/3011380), we know

```
console.log(false ** false == true);  // true
console.log(false ** true == false);  // true
console.log(true ** false == true);  // true
console.log(true ** true == true);  // true

```

I think we can implement [Converse implication](https://en.wikipedia.org/wiki/Converse_implication) through `exponentiation operator` in ES7.

Given the return value of function `f()` and `g()` are `boolean`. So we can use this simple codes

```
if (g() ** f()) { 
   // 
}

```

to replace 

```
if ((g() && f()) || !f()) {
    //
}

```

Some test codes are [here](http://babeljs.io/repl/). Is it valid or not under ES7?