nonmonotonic consequence

Nonmonotonic consequence refers to a type of logical reasoning where conclusions can change when additional information is added. Unlike traditional logic—where adding new facts doesn't undo previous conclusions—nonmonotonic reasoning allows for the possibility that new evidence might lead us to revise or withdraw earlier beliefs. It's common in real-world decision-making, such as medical diagnosis or legal reasoning, where initial assumptions are tentative and may need adjustment as more information becomes available. Essentially, it's a flexible way of reasoning that better models how humans reason in situations with incomplete or evolving information.