Propositional variable: Difference between revisions

Revision as of 13:50, 27 November 2012

Revision as of 14:00, 27 November 2012

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*Given two formulas ''X'' and ''Y'', and a [[binary connective]] ''b'' (such as the [[logical conjunction]] ∧), then ''(X b Y)'' is a formula. (Note the parentheses.)

In this way, all of the formulas of propositional logic are built up from propositional variables as a basic unit. Propositional variables should not be confused with the [[metavariable]]s which appear in the [[Propositional_logic#Example_1._Simple_axiom_system|typical axioms of propositional calculus]]; the latter effectively range over well-formed formulae.

Propositional variables are represented as nullary [[Predicate (mathematical logic)|predicates]] in [[first order logic]]. Propositional variables should not be confused with the [[metavariable]]s which appear in the typical axioms of propositional calculus; the latter effectively range over propositional variables.

==See also==