Formal Notation
The negation of conjunction rule may be written in sequent notation:
The negation of disjunction rule may be written as:
In rule form: negation of conjunction
and negation of disjunction
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: De Morgan's Laws
Famous quotes containing the word formal:
“I will not let him stir
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With wholesome syrups, drugs, and holy prayers,
To make of him a formal man again.”
—William Shakespeare (1564–1616)