Formal Notation
The disjunctive syllogism rule may be written in sequent notation:
where is a metalogical symbol meaning that is a syntactic consequence of, and in some logical system;
and expressed as a truth-functional tautology or theorem of propositional logic:
where, and are propositions expressed in some formal system.
Read more about this topic: Disjunctive Syllogism
Famous quotes containing the word formal:
“Two clergymen disputing whether ordination would be valid without the imposition of both hands, the more formal one said, “Do you think the Holy Dove could fly down with only one wing?””
—Horace Walpole (1717–1797)