Category
page 1Propositions
proposition
Propositions are the meanings of declarative sentences, objects of beliefs, and bearers of truth values. They explain how different sentences, such as the English "Snow is white" and the German "Schnee ist weiß", can have identical meaning by expressing the same proposition. Similarly, they ground the fact that different people can share a belief by being directed at the same content. True propositions describe the world as it is, while false ones fail to do so. Researchers distinguish types of propositions by their informational content and mode of assertion, such as the contrasts between aff
logical contradiction
thumb|This diagram shows the contradictory relationships between categorical propositions in the [[square of opposition of Aristotelian logic.]]
tautology
logical formula which is true in every possible interpretation
tautology
statement which repeats the same idea, using near-synonymous morphemes, words, or phrases
truth value
value indicating the relation of a proposition to truth
contingency
status of propositions that are neither always true nor always false
categorical proposition
proposition that asserts or denies that all or some of the members of one category are included in another
propositional formula
type of logical formula in propositional logic
sentence
in mathematical logic, a well-formed formula with no free variables
atomic sentence
term in logic