S = <phi, phi, phi, phi>Training data = <rainy, cold, normal, change> => No (negative example). How will S be represented after encountering this training data?

Correct Answer: <phi, phi, phi, phi>
Initially S is phi, which implies that the learner is yet to encounter a positive example. S will remain the same after encountering another negative example. It will change only after encountering a positive example.