Premise & hypothesis.
people are standing around smiling.

Nobody is standing.
++++++++++
true or not.
no

Premise & hypothesis.
A man in a red apron is cooking on a grill, while several other men stand around.

people have a summer barbecue
++++++++++
true or not.
it is not possible to tell

Premise & hypothesis.
A man, in a black sweater, fishing.

The man is wearing a white shirt
++++++++++
true or not.
no