Branch of mathematical logic in which we apply the rules and methods of calculation on propositions or propositional forms.

In propositional calculation, we use the propositional variables P, Q, R, S, etc., connectors between these variables, and parentheses with which we define statements or propositions, and we choose some of them as true statements that are then called axioms of propositional calculation.

### Example

\(\neg(\textrm{P}\ ∧ \textrm{Q})↔\neg{\textrm{P}} ∨ \neg{\textrm{Q}}\)