First-order logic Whereas propositional logic assumes the world contains facts, first-order logic (like natural language) assumes the world contains ● -Objects:people,houses,numbers,colors, baseball games,wars,.. -Relations:red,round,prime,brother of, bigger than,part of,comes between,.. -Functions:father of,best friend,one more than nlue First-order logic • Whereas propositional logic assumes the world contains facts, • first-order logic (like natural language) assumes the world contains • – Objects: people, houses, numbers, colors, baseball games, wars, … – – Relations: red, round, prime, brother of, bigger than, part of, comes between, … – Functions: father of, best friend, one more than, plus, …