 Bolzano distinguishes predicate and propositional negation, the former taking the form ‘\(A\) has non-\(b\)’, the latter ‘[\(A\) has \(b\)] has non-truth’ (§189, 1(e); cf. §136). The two forms are not equivalent, since, for example, [Mozart’s 35th piano concerto is not in E-flat] is false, its subject-idea being objectless, while [[Mozart’s 35th piano concerto is in E-flat] has non-truth] is true.