Material nonimplication or abjunction is a term referring to a logic operation used in generic circuits and Boolean algebra. It is the negation of material implication. That is to say that for any two propositions P {\displaystyle P} and Q {\displaystyle Q} , the material nonimplication from P {\displaystyle P} to Q {\displaystyle Q} is true if and only if the negation of the material implication from P {\displaystyle P} to Q {\displaystyle Q} is true. This is more naturally stated as that the material nonimplication from P {\displaystyle P} to Q {\displaystyle Q} is true only if P {\displaystyle P} is true and Q {\displaystyle Q} is false.
It may be written using logical notation as P ↛ Q {\displaystyle P\nrightarrow Q} , P ⊅ Q {\displaystyle P\not \supset Q} , or "Lpq" (in Bocheński notation), and is logically equivalent to ¬ ( P → Q ) {\displaystyle \neg (P\rightarrow Q)} , and P ∧ ¬ Q {\displaystyle P\land \neg Q} .