A '''propositional calculus''' (or a '''sentential calculus''') is a [[formal system]] that represents the materials and the principles of ''propositional logic'' (or ''sentential logic''). Propositional logic is a domain of formal subject matter that is, up to [[isomorphism]], constituted by the structural relationships of mathematical objects called ''[[proposition (mathematics)|proposition]]s''. | A '''propositional calculus''' (or a '''sentential calculus''') is a [[formal system]] that represents the materials and the principles of ''propositional logic'' (or ''sentential logic''). Propositional logic is a domain of formal subject matter that is, up to [[isomorphism]], constituted by the structural relationships of mathematical objects called ''[[proposition (mathematics)|proposition]]s''. |