abductive reasoning al-farabi al-ghazali al-kindi alan turing alfred north whitehead alfred tarski alonzo church answer set programming antinomy argument argumentation theory aristotle autoepistemic logic averroes avicenna axiom axiomatic system belief revision bertrand russell boolean function boolean satisfiability problem charles peirce classical logic cogency completeness computability logic consistency critical thinking david hilbert deductive reasoning deductive system default logic defeasible logic defeasible reasoning deontic logic dharmakirti dialetheism doxastic logic epistemic logic fakhr al-din al-razi fallacy fictionalism finitism first-order logic formal grammar formal interpretation formal language formal proof formal semantics formal system fuzzy logic georg cantor george boole gerhard gentzen giuseppe peano gottlob frege hilary putnam history of logic ibn hazm ibn taymiyyah ibn al-nafis indian logic inductive reasoning inference informal logic intuitionism intuitionistic logic kanada linear logic list of basic topics in logic list of fallacies list of logicians list of mathematical logic topics list of paradoxes list of rules of inference list of set theory topics logic logic in china logic in islamic philosophy logic in computer science logic programming logical atomism logical connective logical consequence logicism lotfi asker zadeh mathematical logic metalogic modal logic model theory monadic predicate calculus mozi nagarjuna negation as failure nominalism organon paraconsistent logic paradox philosophical logic philosophical realism philosophy of logic platonic realism predicate logic proof theory proposition propositional calculus quantification reason reasoning recursion theory relevance logic rudolf carnap rule of inference saul kripke second-order logic set theory shahab al-din suhrawardi soundness stable model semantics stanford encyclopedia of philosophy syllogism table of logic symbols temporal logic term logic theorem thoralf skolem truth table type theory validity well-formed formula willard van orman quine