Propositional Calculus - Basic and Derived Argument Forms

Basic and Derived Argument Forms
Name Sequent Description
Modus Ponens If then ; ; therefore
Modus Tollens If then ; not ; therefore not
Hypothetical Syllogism If then ; if then ; therefore, if then
Disjunctive Syllogism Either or, or both; not ; therefore,
Constructive Dilemma If then ; and if then ; but or ; therefore or
Destructive Dilemma If then ; and if then ; but not or not ; therefore not or not
Bidirectional Dilemma If then ; and if then ; but or not ; therefore or not
Simplification and are true; therefore is true
Conjunction and are true separately; therefore they are true conjointly
Addition is true; therefore the disjunction ( or ) is true
Composition If then ; and if then ; therefore if is true then and are true
De Morgan's Theorem (1) The negation of ( and ) is equiv. to (not or not )
De Morgan's Theorem (2) The negation of ( or ) is equiv. to (not and not )
Commutation (1) ( or ) is equiv. to ( or )
Commutation (2) ( and ) is equiv. to ( and )
Commutation (3) ( is equiv. to ) is equiv. to ( is equiv. to )
Association (1) or ( or ) is equiv. to ( or ) or
Association (2) and ( and ) is equiv. to ( and ) and
Distribution (1) and ( or ) is equiv. to ( and ) or ( and )
Distribution (2) or ( and ) is equiv. to ( or ) and ( or )
Double Negation is equivalent to the negation of not
Transposition If then is equiv. to if not then not
Material Implication If then is equiv. to not or
Material Equivalence (1) ( is equiv. to ) means (if is true then is true) and (if is true then is true)
Material Equivalence (2) ( is equiv. to ) means either ( and are true) or (both and are false)
Material Equivalence (3) ( is equiv. to ) means, both ( or not is true) and (not or is true)
Exportation from (if and are true then is true) we can prove (if is true then is true, if is true)
Importation If then (if then ) is equivalent to if and then
Tautology (1) is true is equiv. to is true or is true
Tautology (2) is true is equiv. to is true and is true
Tertium non datur (Law of Excluded Middle) or not is true
Law of Non-Contradiction and not is false, is a true statement

Read more about this topic:  Propositional Calculus

Famous quotes containing the words basic, derived, argument and/or forms:

    The basic tool for the manipulation of reality is the manipulation of words. If you can control the meaning of words, you can control the people who must use the words.
    Philip K. Dick (1928–1982)

    Jesus wept; Voltaire smiled. From that divine tear and from that human smile is derived the grace of present civilization.
    Victor Hugo (1802–1885)

    “English! they are barbarians; they don’t believe in the great God.” I told him, “Excuse me, Sir. We do believe in God, and in Jesus Christ too.” “Um,” says he, “and in the Pope?” “No.” “And why?” This was a puzzling question in these circumstances.... I thought I would try a method of my own, and very gravely replied, “Because we are too far off.” A very new argument against the universal infallibility of the Pope.
    James Boswell (1740–1795)

    It is given to few to add the store of knowledge, to strike new springs of thought, or to shape new forms of beauty. But so sure as it is that men live not by bread, but by ideas, so sure is it that the future of the world lies in the hands of those who are able to carry the interpretation of nature a step further than their predecessors.
    Thomas Henry Huxley (1825–95)