[Q] Given the sentence "A snowboarder slides across an icy table." is it true that "Snowboarder displays his skills."?
[A] Sliding across an icy table requires skills and the fact that a snowboarder slides across an icy table implies he is displaying his skills.
The answer is yes.

[Q] Given the sentence "A man does ti chi on a rock overlooking a forest." is it true that "A man is contemplating life on a rock."?
[A] A man does Ti Chi on a rock overlooking a forest does not indicate that he is contemplating life on a rock.
The answer is it is not possible to tell.

[Q] Premise: "A group of men standing around talking outdoors."
Hypothesis: "A man stands alone outside."
Do we know that the hypothesis entailed by the premise?
[A] Group of men implies more than one person while man is singular.
The answer is no.