The umpire measure is defined at the level of truth functions, but can also be understood in terms of its implied judgments at the syntactic level. Interpreted this way, <math>\Upsilon_1\!</math> recognizes theorems of the propositional calculus over <math>[x, y],\!</math> giving a score of "1" to tautologies and a score of "0" to everything else, regarding all contingent statements as no better than falsehoods. | The umpire measure is defined at the level of truth functions, but can also be understood in terms of its implied judgments at the syntactic level. Interpreted this way, <math>\Upsilon_1\!</math> recognizes theorems of the propositional calculus over <math>[x, y],\!</math> giving a score of "1" to tautologies and a score of "0" to everything else, regarding all contingent statements as no better than falsehoods. |