2-element Boolean algebra
Name: B2=⟨{0,1},∨,0,∧,1,′⟩
Elements: 0,1
Constant operations
0=0
1=1
Unary operations
Complement = negation = 1−x =
| x | 0 | 1 |
|---|---|---|
| x′ | 1 | 0 |
Alternative notation: −x=¯x=x−=¬x
Binary operations
Join = or = truncated addition = min{x+y,1} =
| ∨ | 0 | 1 |
|---|---|---|
| 0 | 0 | 1 |
| 1 | 1 | 1 |
Meet = and = multiplication =
| ∧ | 0 | 1 |
|---|---|---|
| 0 | 0 | 0 |
| 1 | 0 | 1 |
Derived operations
Symmetric difference: x⊕y=(x∨y)∧(x∧y)′ = (x∧y′)∨(y∧x′)
| ⊕ | 0 | 1 |
|---|---|---|
| 0 | 0 | 1 |
| 1 | 1 | 0 |
Implication: x→y=x′∨y
| → | 0 | 1 |
|---|---|---|
| 0 | 1 | 1 |
| 1 | 0 | 1 |
Bi-implication: x↔y=(x→y)∧(y→x)
| ↔ | 0 | 1 |
|---|---|---|
| 0 | 1 | 0 |
| 1 | 0 | 1 |
Nand: x|y=(x∧y)′
| | | 0 | 1 |
|---|---|---|
| 0 | 1 | 1 |
| 1 | 1 | 0 |
Nor: x↓y=(x∨y)′
| ↓ | 0 | 1 |
|---|---|---|
| 0 | 1 | 0 |
| 1 | 0 | 0 |
Properties
| Simple | Yes |
|---|---|
| Subdirectly irreducible | Yes |
Basic results
This algebra generates the variety of all Boolean algebras.
Every Boolean algebra is a subdirect product of B2.
Maximal subalgebras
none
Minimal superalgebras
Maximal homomorphic images
Minimal homomorphic preimages
Maximal subvarieties
Minimal supervarieties
???