Boolean LogicKey Facts
Common Boolean Identities (Simplification Rules)
Part of Boolean Expressions — GCSE Computer Science
This key facts covers Common Boolean Identities (Simplification Rules) within Boolean Expressions for GCSE Computer Science. Revise Boolean Expressions in Boolean Logic for GCSE Computer Science with 15 exam-style questions and 22 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 10 of 11 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 10 of 11
Practice
15 questions
Recall
22 flashcards
Common Boolean Identities (Simplification Rules)
Some Boolean expressions can be simplified using mathematical identities:
| Identity Name | Expression | Simplifies To | Explanation |
|---|---|---|---|
| Identity Law | A AND 1 | A | ANDing with 1 doesn't change A |
| Identity Law | A OR 0 | A | ORing with 0 doesn't change A |
| Null Law | A AND 0 | 0 | ANDing with 0 always gives 0 |
| Null Law | A OR 1 | 1 | ORing with 1 always gives 1 |
| Complement Law | A AND NOT(A) | 0 | Contradiction - can't be both true and false |
| Complement Law | A OR NOT(A) | 1 | Tautology - always true (A is either 1 or 0) |
| Double Negation | NOT(NOT(A)) | A | Two NOTs cancel out |
| Absorption | (A AND B) OR A | A | If A is true, whole expression is true |