Search results
Results from the WOW.Com Content Network
Double negation elimination and double negation introduction are two valid rules of replacement. They are the inferences that, if not not-A is true, then A is true, and its converse, that, if A is true, then not not-A is true, respectively. The rule allows one to introduce or eliminate a negation from a formal proof.
In particular, systems of intuitionistic logic do not assume the law of the excluded middle and double negation elimination, which are fundamental inference rules in classical logic. Formalized intuitionistic logic was originally developed by Arend Heyting to provide a formal basis for L. E. J. Brouwer's programme of intuitionism.
One obtains the rules for intuitionistic negation the same way but by excluding double negation elimination. Negation introduction states that if an absurdity can be drawn as conclusion from then must not be the case (i.e. is false (classically) or refutable (intuitionistically) or etc.). Negation elimination states that anything follows from ...
Implication introduction / elimination (modus ponens) Biconditional introduction / elimination; Conjunction introduction / elimination; Disjunction introduction / elimination; Disjunctive / hypothetical syllogism; Constructive / destructive dilemma; Absorption / modus tollens / modus ponendo tollens; Negation introduction; Rules of replacement
Download as PDF; Printable version; ... Markov's rule is the formulation of Markov's principle as a rule. ... Assuming classical double-negation elimination, the weak ...
Minimal logic proves double-negation elimination for negated formulas, () (). More generally, Heyting arithmetic proves this classical equivalence for any Harrop formula . And Σ 1 0 {\displaystyle \Sigma _{1}^{0}} -results are well behaved as well: Markov's rule at the lowest level of the arithmetical hierarchy is an admissible rule of ...
A set of rules can be used to infer any valid conclusion if it is complete, while never inferring an invalid conclusion, if it is sound. A sound and complete set of rules need not include every rule in the following list, as many of the rules are redundant, and can be proven with the other rules.
The case = now directly shows how double-negation elimination implies consequentia mirabilis over minimal logic. In intuitionistic logic, explosion can be used for ⊥ → ( P ∧ ⊥ ) {\displaystyle \bot \to (P\land \bot )} , and so here the law's special case consequentia mirabilis also implies double-negation elimination.