She did not leave the door shut. (affirmative)

Answer:She left the door shut (if you still need it)

Explanation:

The sentence which speaks about the noun which is only positive.

The negative sentence is not applicable to indicate this type of sentences.

For example, the new born baby isn't a girl, when the actual meaning of the sentence is the new born baby is a boy.

These types of sentences describe about the subjects whom has an active action to do and they give the positive approach about the noun present in the sentence and which is in motion.