Dokazati skupovnu jednakost: A\(B∩C) = (A\B) ∪ (A\C)
x ∈ A\(B∩C) <=> x ∈ A ∧ ¬(x ∈ B∩C)
<=> x ∈ A ∧ ¬(x ∈ B ∧ x ∈ C)
<=> x ∈ A ∧ (¬(x ∈ B) ∨ ¬(x ∈ C)) (DeMorganov zakon)
<=> ( x ∈ A ∧ ¬(x ∈ B) ) ∨ ( x ∈ A ∧ ¬(x ∈ C) ) (distributivnost konjukcije prema disjunkciji)
<=> ( x ∈ A\B ) ∨ ( x ∈ A\C )
<=> x ∈ (A\B) ∪ (A\C)