Definition:Conjugate Statements

Definition

Let $p$ and $q$ be statements.

The conditional statement:

$p \implies q$

its inverse:

$\lnot p \implies \lnot q$

its converse:

$q \implies p$

and its contrapositive:

$\lnot q \implies \lnot p$

are all conjugate statements.

Sources

• 1946: Alfred Tarski: Introduction to Logic and to the Methodology of Deductive Sciences (2nd ed.) ... (previous) ... (next): $\S \text{II}.14$: Application of laws of sentential calculus in inference