(Lat., saving the truth) Two expressions are intersubstitutable salva veritate if the result of substituting one for the other always preserves the truth-value of any sentence in which they are used. If the language is sufficiently strong to express fine distinctions, then this will be a criterion of sameness of meaning. But if the language has only the kinds of context treated in the predicate calculus, we can only conclude that the two expressions have the same extension.
Philosophy dictionary. Academic. 2011.