Error on Ch.6 Example - "Coding Script Evaluation" pg. 115

[vvronskyFX]

The desired outcome should print "True":

The error I am receiving is this:

It's getting a "NotImplementedError: "

I've completed all other exercises to close out the chapter and this error still persists. Am I missing something here?

[Yuji-Kakeya]

@vvronskyFX
Have you completed the exercise No.2?
If you edited op.py directly, you might want to try restarting the kernel, as the cache may be the cause.