QUESTION: Given the sentence "Person wearing a black hat lets a cat sit on their shoulder." is it true that "A witch wearing a black hat lets a cat sit on her shoulder."?

Let's solve it slowly: Sentence 1: Person wearing a black hat lets a cat sit on their shoulder. Sentence 2: A witch wearing a black hat lets a cat sit on her shoulder.
The answer is it is not possible to tell.

QUESTION: Premise: "A man is flailing in water while holding up a drink can."
Hypothesis: "There is a man in the water."
Do we know that the hypothesis entailed by the premise?

Let's solve it slowly: To be flailing in the waiter can't happen unless you are in the water.
The answer is yes.

QUESTION: Given the sentence "He is smiling while having a drink." is it true that "He is frowning at the glass next to him."?

Let's solve it slowly:
He is either smiling while heaving a drink or frowning at the glass next to him.
The answer is no.