His analysis is relatively conservative, being in terms of existential quantification
over choice functions, the existential term itself being the result of applying a choice function to a predicate, hence of type e (an analysis that is considerably simpler than his previous higher-order quantification-over-determiner values--Winter 1997).
Assuredly, Morscher explicitly acknowledges that Bolzano has ways to deal with conjunction, disjunction, conditionality, negation, existential quantification
and relational predicates that are consistent with the idea that all propositions have the form 'A has b'.
Finally, some authors (Bach, Recanati) embrace the role of unarticulated constituents in the content expressed; others (Cappelen & Lepore) resist it, or limit it to existential quantification