Defeasible logic

Defeasible logic is a way of looking at arguments and concluding how one argument might be more likely to be true than another. It's like a game - you set up two sides, one side (called the bearer) has to prove why their argument and conclusion is true, and the other side (called the challenger) has to prove why their argument is more likely to be true. The outcome of the game depends on who has the stronger argument.