I think it makes sense to only do this check if we're going to return false:

```
                if (result.equal) {
                    // Correct answer
                    return true;
                } else if (result.message) {
                    // Nearly correct answer
                    return result.message;
                } else if (xUsedAsMultOp(guess)) {
                    return "Use *, not x, for multiplication.";
                } else {
                    // Wrong answer
                    return false;
                }
```

though this probably actually makes more sense as a part of the KAS repo so that we don't need to reimplement it everywhere it's used. Do you mind submitting as a pull request there instead?