Given the task definition, example input & output, solve the new input case.
Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.
Example: Question: What's the difference between the following examples: Neither of my teachers are mathematicians. None of my teachers are mathematicians.
Answer: Neither - not either - implies that there is a choice of only two. So 'neither of my teachers' is only correct if there are exactly two teachers, 'none of my teachers' can be any number.
Output: yes
The answer is well in context with the question and gives a proper explanation to resolve it. Hence, the output "yes" is correct.

New input case for you: Question: What's the difference between these two phrases?
Answer: To add to Martha's answer: The simple past ("Did you see this") refers about an event in the past The present perfect ("Have you seen this") suggests a link with the present time. If "this" is something you could have seen but cannot anymore (you should have been there seeing "this" at the time, but it wouldn't have the same impact if you see it again now), then "Did you see" is more appropriate. It is about an event that happened once in the past. If "this" is something you can check out whenever you want, "Have you seen" is more to the point, because it suggests that, if you haven't seen it in the past, you could consider seeing it now or in the near future. It is about an event which can happen again or is still relevant in the present.
Output:
yes