[Q] Premise: "A guy doing a wallride on his bike."
Hypothesis: "A guy is fixing his bike."
Do we know that the hypothesis entailed by the premise?
[A] Either the guy is doing a wallride on his bike or he is fixing said bike. He cannot do both at the same time.
The answer is no.

[Q] Premise: "A man in black shorts is walking down the sidewalk."
Hypothesis: "There is a man walking."
Do we know that the hypothesis entailed by the premise?
[A] There has to physically be a man for there to be a man walking.
The answer is yes.

[Q] Given the sentence "The man wearing the brown jacket is holding a cigarette and the man behind him is holding a can of beer." is it true that "Two men are smoking pipes as they share a bottle of wine."?
[A] Pipes and a cigarette are as different as wine is to beer.
The answer is no.