Material nonimplication

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Material nonimplication or abjunction (latin ab = "from", junctio =–"joining") is the negation of material implication. That is to say that for any two propositions P and Q, the material nonimplication from P to Q is true if and only if not P implies Q. This is more naturally stated as that the material nonimplication from P to Q is true only if P is true and Q is false.

It may be written using logical notation as:

p⊅q
Lpq
p↛q

And is equivalent to:

p∧~q

Definition

Truth table

p q ~\nrightarrow
T T F
T F T
F T F
F F F

Properties

falsehood-preserving: The interpretation under which all variables are assigned a truth value of "false" produces a truth value of "false" as a result of material nonimplication.

Symbol

The symbol for material nonimplication is simply a crossed-out material implication symbol. Its Unicode symbol is 8603 (decimal).

Natural language

Grammatical

Rhetorical

"p but not q."

Boolean algebra

(A'+B)'

Computer science

Bitwise operation: A&(~B)

Logical operation: A&&(!B)

See also

References