− | Classical logic is based on propositions. It is often said that a proposition is a sentence that asks whether the proposition is true or false. Indeed, a proposition in mathematics is usually either true or false, but this is obviously a little too vague to be a definition. It can be taken, at best, as a warning: if a sentence, expressed in common language, makes no sense to ask whether it is true or false, it will not be a proposition but something else.
| + | La lógica clásica se basa en las proposiciones. A menudo se dice que una proposición es una frase que pregunta si la proposición es verdadera o falsa. De hecho, una proposición en matemáticas suele ser verdadera o falsa, pero esto es obviamente demasiado vago para ser una definición. It can be taken, at best, as a warning: if a sentence, expressed in common language, makes no sense to ask whether it is true or false, it will not be a proposition but something else. |
| It can be argued whether or not common language sentences are propositions as in many cases it is not often evident if a certain statement is true or false. | | It can be argued whether or not common language sentences are propositions as in many cases it is not often evident if a certain statement is true or false. |