 By defining in a direct way how the meanings of different parts of language go together to yield sentence meanings, these approaches are not under pressure to identify the meanings of sentences true in all the same possible circumstances, or even sentences which are logically equivalent. So it is easy to see how a general algebraic approach can make room for hyperintensional differences between parts of language. Even if sentence meanings are necessarily equivalent, if they relate differently to a “believes that” operator they do not have to be substitutable in “John believes that \(A\)” contexts. Bealer (1979) touts this flexibility as an advantage in dealing with puzzles like the semantics of belief attributions, as does Menzel (1993).