Boolean algebra

¬ is NOT, ∧ is AND, ∨ is OR. Work out ¬ first, then ∧, then ∨. You can type ! or ~ for ¬, . or & for ∧, and + or | for ∨.

De Morgan's laws in words: break the bar and change the sign. NOT a bracket becomes NOT each part, with ∧ and ∨ swapped. It works backwards too: ¬A ∨ ¬B ≡ ¬(A ∧ B).