Operations with sets. Examples of formulas in algebra of sets

1. Operations with sets

Addition (union) A + B = A ∪ B = {x ∈ A + B: x ∈ A or x ∈ B}

Multiplication (interesection) A · B = A ∩ B = {x ∈ A · B: x ∈ A and x ∈ B}