  There may be functors whose arguments are functors: for example a conjunction holding between two binary predicates has a category  \(\rS\langle\rS\langle\rN\rN\rangle\rS\langle\rN\rN\rangle \rangle\).  There may also be what are called many-link functors, which are functors whose values are functors. For example, the English morpheme ‘–ly’ converts an adjective, category  \(\rN\langle\rN\rangle\),  into an adverb, for example of category   \(\rS\langle\rN\rangle \langle\rS\langle\rN\rangle \rangle\),  so ‘–ly’ has effective category  \(\rS\langle\rN\rangle \langle\rS\langle\rN\rangle \rangle \langle\rN\langle\rN\rangle \rangle\).   In some subsequent categorial grammars, transitive verbs are quite plausibly taken to have the many-link category  \(\rS\langle\rN\rangle \langle\rN\rangle\)  rather than the binary predicate category   \(\rS\langle\rN\rN\rangle\).  This move is indeed a standard trick in logic, first introduced by Moses Schönfinkel in 1924, for dispensing with many-placed functors in favor of many-link but one-placed functors. Had he known of this, Leśniewski would no doubt have disapproved. While there is no loss of logical power in eliminating many-placed functors, the move is unnatural, and Leśniewski would not have countenanced defining many-placed functors as many-link ones in disguise, as we find in Church for instance.