Logic puzzle 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 we are given a list of premises and asked what can be deduced from them, are known
Exportation (logic) Exportation (logic) Exportation is a valid rule of replacement in propositional logic. The rule allows conditional statements having conjunctive antecedents to be replaced by statements having conditional consequents and vice versa in logical proofs. It is the rule that: formula_1 Where "formula_2" is a metalogical symbol representing "can be replaced in a proof with." The "exportation" rule may be written in sequent notation: where formula_4 is a metalogical symbol meaning that formula_5 is a syntactic equivalent of formula_6 in some logical system; or in rule form: where the rule is that wherever an instance of "formula_9" appears on a line