Logic puzzle might be present in lieu of a grid in a puzzle about the location of different shops. Logic puzzle A logic puzzle is a puzzle deriving from the mathematics field of deduction. The logic puzzle was first produced by Charles Lutwidge Dodgson, who is better known under his pen name Lewis Carroll, the author of "Alice's Adventures in Wonderland". In his book "The Game of Logic" he introduced a game to solve problems such as confirming the conclusion "Some greyhounds are not fat" from the statements "No fat creatures run well" and "Some greyhounds run well". Puzzles like this, where
Default logic is true. The logical formulae in and all formulae in a default were originally assumed to be first-order logic formulae, but they can potentially be formulae in an arbitrary formal logic. The case in which they are formulae in propositional logic is one of the most studied. The default rule “birds typically fly” is formalized by the following default: This rule means that, if is a bird, and it can be assumed that it flies, then we can conclude that it flies. A background theory containing some facts about birds is the following one: According to this default rule, a