The intended interpretations of the symbols are:ĭo the rules make sense, intuitively, under this interpretation? Here are informalĪrguments to justify five of the nine rules:

Switcheroo Rule: and are interchangeable.DeMorgan's Rule: and ~ are interchangeable.Contrapositive Rule: and are interchangeable.

Rule of Detachment: If A and are theorems,.Carry-over Rule: Inside a fantasy, any theorem from the reality one level higher.Fantasy Rule: If assuming A to be a theorem leads to B.Provided the resulting string is well-formed. The string ~~ can be added into any theorem to make a new theorem, Double-Tilde Rule: The string ~~ can be deleted from any theorem to.Rule of Separation: If is a theorem, then.Rule of Joining: If A and B are theorems,.Here A and B stand for arbitrary formulas. Recursively as follows, with v ranging over variables, and A The set of formulae, also known as well-formed strings, is defined Only truth values are true and false and the four operators not,Īnd, or, and if-then, are all truth functional. 195)Ĭlassical propositional logic is a kind of propostional logic in which the The propositional calculus can easily be extended to include are very few in number, and they are very simple, an example of a system with a purpose - to represent part of the architecture

Reasoning about propositions, that is, atomic declarations that have truth values. Propositional Logic, or the Propositional Calculus, is a formal logic for The propositional calculus is a great first logistic system

Subsume propositional logic