Deductive reasoning Deductive reasoning Deductive reasoning, also deductive logic, logical deduction is the process of reasoning from one or more statements (premises) to reach a logically certain conclusion. Deductive reasoning goes in the same direction as that of the conditionals, and links premises with conclusions. If all premises are true, the terms are clear, and the rules of deductive logic are followed, then the conclusion reached is necessarily true. Deductive reasoning (""top-down logic"") contrasts with inductive reasoning (""bottom-up logic"") in the following way; in deductive reasoning, a conclusion is reached reductively by applying general rules which hold over the entirety of a
Logical NOR Logical NOR In boolean logic, logical nor or joint denial is a truth-functional operator which produces a result that is the negation of logical or. That is, a sentence of the form ("p" NOR "q") is true precisely when neither "p" nor "q" is true—i.e. when both of "p" and "q" are "false". In grammar, nor is a coordinating conjunction. The NOR operator is also known as Peirce's arrow—Charles Sanders Peirce introduced the symbol ↓ for it, and demonstrated that the logical NOR is completely expressible: by combining uses of the logical NOR it is possible to express any logical