Nonmonotonic logic is a type of logic that allows for the reasoning process to be flexible and adaptable. Unlike traditional logic, where conclusions drawn from a set of premises remain valid even when new information is added, nonmonotonic logic permits the possibility that new information can change previous conclusions. This makes it particularly useful in real-world scenarios where knowledge is incomplete or evolving. One common application of nonmonotonic logic is in artificial intelligence, where systems must make decisions based on uncertain or changing information. By using nonmonotonic reasoning, AI can revise its beliefs and conclusions as new data becomes available, leading to more accurate and relevant outcomes in complex situations.