22May/080
Propositional and Predicate Logic
A Proposition is a declarative sentence, which may be shown to be either true, or false, whether the statement is true or false is not - however - relevant. Both "1+2-=3" and "1+2=4" are example of propositions. Predicate logic allows us to explore the truthfulness of a statement, it has an expressive power which propositional logic does not.
17May/080
De Morgan's Theorum
Augustus De Morgan was a 19th century mathematician working in the field of propositional logic, he established a series of rules concerned with conversion between different operators using inversion. The fundamental basis of his theory is that NOT ( P AND Q) = (NOT P) OR (NOT Q), and similarly NOT (P OR Q) = (NOT P) AND (NOT Q), this is often known as De Morgan Duality.