How is the gerundive construction to be analyzed in the following example?
Cariotae cum ficis certandum habent. (Plin. Ep. 1,8)
'Dates have to fight with figs'.
Could you please provide me with some similar examples of "(in)transitive" HAVE constructions in Latin? Here I write "(in)transitive" because there is no explicit NP object. NB: these "(in)transitive" examples are different from the typical (and, indeed, expected!) ones, namely, the clearly transitive ones where there is an explicit object: e.g., see the following example from Joonas's answer below, which is also included in a previous related question (How many types of so-called “predicative Gerundives” can be differentiated in Latin? ):
Ibi agrum de nostro patre colendum habebat. (Ter. Phorm. 364-365)
‘He had there a piece of land from my father to farm’.
Importantly, as pointed out below by Joonas, these transitive examples of predicative gerundive are by far more frequent than the "(in)transitive" ones at issue here.
As is well-known, there is an important parallelism between transitive habere + accusative and intransitive esse + dative constructions, which holds in different domains of Latin grammar. E.g., cf. Caesar equitatum coactum habebat (Caes. Bell. Gall. 1,15) with Caesari equitatus coactus erat.
According to the abovementioned parallelism, the nominative subject cariotae can also be converted into the so-called "dativus auctoris" or "dative of agent": cariotis.
Cariotis cum ficis certandum est.
This second construction is clearly impersonal, i.e., with no personal subject (cf. the typical impersonal passive construction Pugnatum est acriter; see also the previous post for the impersonal construction Nunc est bibendum: Nunc est bibendum: gerund or gerundive? ) but what about the object of the allegedly transitive verb habent in the first example above from Pliny? Assuming that certandum is gerundive (and hence a verbal adjective), how should one analyze the (null) object of transitive habent in Pliny's example? Basically, we do have "null expletive subjects" in Latin (e.g., cf. Lat. Pluit and Engl. *(It) is raining or cf. Lat. Pugnatum est acriter and Engl. *(It) was fought fiercely Vid. http://www.glottopedia.org/index.php/Expletive_noun_phrase // https://en.wikipedia.org/wiki/Dummy_pronoun ) but do we have "null expletive objects" in Latin as well? How is the grammatical construction certandum habent above to be analyzed? I know what Pliny's example means but I do not know how to analyze it properly. My preliminary analysis would be that in this example there is a null expletive object pronoun involved (which would be the counterpart of the null expletive subject pronoun in the impersonal construction above with certandum est) and the verbal adjective certandum is then predicated of this null object pronoun in Pliny's example. But I'm not entirely convinced by this analysis because positing a null expletive object pronoun here can be said to be too stipulative: after all, in which other constructions should one posit such a null expletive object pronoun? In striking contrast to that, notice that the analysis of Caesar equitatum coactum habebat is indeed very transparent: i.e., the passive participle coactum is predicatively applied to the direct object of the transitive verb habebat, namely, equitatum. Exactly the same with Terence's example above.
NB: the Latin construction at issue developed into a grammaticalized verbal periphrasis of obligation, which is, for example, formed in Catalan with 'haver' de + infinitive (cf. also Engl. above: Dates have to fight with figs). Given this, one could simply claim that in Latin the very same happens (i.e., the construction in Latin is fully grammaticalized like in Romance and English) but I don't think so. My intuition is that the verb habere in the Latin construction above is not as (strongly) grammaticalized as in Romance and English. So a different analysis is involved.