Anchor: Two people are outside walking their dog.
Entailed: Two people are walking a dog.
Contradiction: Two people are walking their cat outside.
Contradiction: It is for those who prefer the summer time. 
Contradiction: Ah! He said, surprised.
Contradiction: There's no need for us to stick to the subject, the people doing this work don't matter.
Contradiction: He pulls the cart on the sidewalk.