Logical equivalence
In logic and mathematics, two statements are logically equivalent if they can prove each other (under a set of axioms),[1] or have the same truth value under all circumstances. In propositional logic, two statements are logically equivalent precisely when their truth tables are identical.[2] To express logical equivalence between two statements, the symbols [math]\displaystyle{ \equiv }[/math], [math]\displaystyle{ \Leftrightarrow }[/math] and [math]\displaystyle{ \iff }[/math]are often used.[3][4]
For example, the statements "A and B" and "B and A" are logically equivalent.[2] If P and Q are logically equivalent, then the statement "P if and only if Q" is a tautology.[4]
Related pages
References
- ↑ The Definitive Glossary of Higher Mathematical Jargon (in en-US). Math Vault (2019-08-01). Retrieved 2020-10-09.
- ↑ 2.0 2.1 Section 1.1: Logical Forms and Equivalencies. www.csm.ornl.gov. Retrieved 2020-10-09.
- ↑ Comprehensive List of Logic Symbols (in en-US). Math Vault (2020-04-06). Retrieved 2020-10-09.
- ↑ 4.0 4.1 2.5: Logical Equivalences (in en). Mathematics LibreTexts (2019-08-13). Retrieved 2020-10-09.