Cheatography

# Boolean Algebra Laws Cheat Sheet by theTrueEnder

Boolean Algebra Laws and theorems cheat sheet

### Operations with 0 and 1:

 1. X + 0 = X 1D. X·1 = X 2. X + 1 = 1 2D. X·0 = 0

### Idempotent Laws:

 3. X + X = X 3D. X·X = X

### Involution Law:

 4. (X´)´ = X

### Laws of Comple­men­tarity:

 5. X + X´ = 1 5D. X·X´ = 0

### Commut­ative Laws"

 6. X + Y = Y + X 6D. XY = YX

### Associ­ative Laws:

 7. (X + Y) + Z = X + (Y + Z) = X + Y + Z 7D. (XY)Z = X(YZ) = XYZ

### Distri­butive Laws:

 8. X(Y + Z) = XY + XZ 8D. X + YZ = (X + Y)(X + Z)

### Simpli­fic­ation Theorems:

 9. XY + XY´ = X 9D. (X + Y)(X + Y´) = X 10. X + XY = X 10D. X(X + Y) = X 11. X(X´ + Y) = XY 11D. X + X´Y = X + Y
Try these first.

### DeMorgan's Laws:

 12. (X + Y + Z + . . .)´ = X´Y´Z´. . . 12D. (XYZ. . .)´ = X´ + Y´ + Z´ + . . .

### Duality:

 13. (X + Y + Z)^D = XYZ. . . 13D. (XYZ. . .)^D = X + Y + X + . . .
Almost never used.

### Multip­lying Out & Factoring Theorem

 14. (X + Y)(X´ + Z) = XZ + X´Y 14D. XY + X´Z = (X + Z)(X´ + Y)

### Consensus Theorem:

 15. XY + YZ + X´Z = XY + YZ 15D. (X + Y)(Y + Z)(X´ + Z) = (X + Y)(X´ + Z)
If Simpli­fic­ation Theorems don't work, try this.

### XOR & XNAND

 XOR: X @ Y = X´Y + XY´ XNAND: (X @ Y)´ X = Y = X´Y´ + XY