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intuitionistic logic (Topic)
IntuitionisticLogic

"intuitionistic logic" is owned by gribskoff.
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See Also: an outline of Hilbert's programme, foundations of mathematics: overview, logicism, quantum topos, interpretation of intuitionistic logic by means of functionals, the inclusion of classical into intuitionistic logic, mathematical platonism

Other names:  Brouwer's logic, intuitionistic foundations
Also defines:  intuitionistic proof, functionals
Keywords:  constructive proof, Evidenz, Heyting's formal system, functionals

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the inclusion of classical into intuitionistic logic (Topic) by gribskoff
interpretation of intuitionistic logic by means of functionals (Topic) by gribskoff
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Cross-references: maps, operation, sort, axiom of choice, effective, identity, finite, contains, extensional, restrictions, denotation, reductio ad absurdum, square, free variables, useful, IND, induction hypothesis, substitution rule, basis, length, induction, complete, derivable, theorem, Peirce's law, tautologies, divergent, states, simple, invertible, analysis, invalid, application, modus ponens, de Morgan's law, conditional, hypothesis, valid, axioms, first order, propositional calculus, variables, arithmetic, minimal, Calculus, represent, function, numbers, parameter, propositions, potential, force, infinite, quantifiers, domain, outcome, element, universal, natural number, segment, mean, ordinal numbers, ideal, ring, definitions, admissible, closure properties, class, closure axioms, Greek letters, argument, sequence, reference, operators, interpretation, normal form, truth function, implies, reduced, propositional functions, negation, contradiction, constant, formulas, existential quantifier, universal quantifier, premises, implication, disjunction, conjunction, connectives, derivations, clauses, natural deduction, composition, composite, place, prime, corollary, entail, language, predicate, terms, reflection, source, duality, inner, NOR, topological spaces, open subsets, integrate, axiomatics, function theory, set theory, member, proof, opposite, similar, logicism, logic, reduction, even, objects, range, foundations, theory, sections, level, classical logic
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This is version 82 of intuitionistic logic, born on 2008-10-07, modified 2008-12-08.
Object id is 11153, canonical name is IntuitionisticLogic.
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Classification:
AMS MSC03-01 (Mathematical logic and foundations :: Instructional exposition )
 03A05 (Mathematical logic and foundations :: Philosophical and critical)
 03B20 (Mathematical logic and foundations :: General logic :: Subsystems of classical logic )

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(P => Q) V (Q => P) by Jon Awbrey on 2008-12-07 13:37:42
I've been puzzling over the following statement in your section on Peirce's law:

"It should be remarked that there are counter-intuitive tautologies of the classical propositional calculus whose validity is secured by bivalence alone and they are not intuitionistically valid."

I've been thrashing out my struggles to understand this at the following location:

http://mywikibiz.com/Talk:Logical_graph#Logical_Graph_Sandbox

Maybe it would help me understand the intuitionistic way of looking at things if you could comment on the notes that I've put there.

The problem with Peirce's law still puzzles me, but I think I'm beginning to see what's going on with the "classical disjunction". If you write it as (P =< Q) V (Q =< P) then it's clear it would hold more generally when the values of propositions are linearly ordered, even when there are more than two of them. So it's more exactly due to dichotomy than bivalence.

On a more complete analysis, there doesn't seem to be any real disagreement between the two schools on this score.

Anyhow, that's how it looks to me at the moment ...

Jon Awbrey
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