Logical Connectives
AND, OR, NOT, implication and biconditional.
Key idea
AND, OR, NOT, implication and biconditional.
In depth
Connectives build compound statements: not (¬), and (∧), or (∨), implies (→), if and only if (↔). The truth of a compound depends only on the truth of its parts. In mathematics, "or" is inclusive.
Worked example
"2 is even and 3 is even" is false, while "2 is even or 3 is even" is true.
Formula
Real-world uses
- Writing search filters (AND, OR, NOT) and program conditions such as “age ≥ 18 and has ID”
Common mistake
Reading "or" as exclusive; p ∨ q is true when both are true.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Logical Connectives?
AND, OR, NOT, implication and biconditional. It is a topic at the intermediate level in Discrete Math & Number Theory.
What is the formula for Logical Connectives?
The key formula is p ∧ q, p ∨ q, ¬p, p → q.
Where is Logical Connectives used in real life?
Real-world examples: Writing search filters (AND, OR, NOT) and program conditions such as “age ≥ 18 and has ID”.
What should I learn before Logical Connectives?
Make sure you are comfortable with Statements and Truth Values, the previous topic in Discrete Math & Number Theory.
What is a common mistake with Logical Connectives?
Reading "or" as exclusive; p ∨ q is true when both are true.
How can I practise Logical Connectives?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Logical Connectives?
Move on to Truth Tables next.
Related intermediate topics in Discrete Math & Number Theory
- Statements and Truth Values – A proposition is true or false, never both.
- Truth Tables – List all truth assignments to evaluate compound statements.
- Subsets and Power Sets – A set with n elements has 2ⁿ subsets.
- Set Operations – Union, intersection, difference and complement.
- Venn Diagrams – Pictures of sets and their overlaps.
- Cartesian Products – All ordered pairs from two sets.