Abstract: The complex organization of syntax in hierarchical structures is one of the core design features of human language. Duality of patterning refers for instance to the organization of the meaningful elements in a language at two distinct levels: a combinatorial level where meaningless forms are combined into meaningful forms and a compositional level where meaningful forms are composed into larger lexical units. The question remains wide open regarding how such a structure could have emerged. Furthermore a clear mathematical framework to quantify this phenomenon is still lacking. The aim of this paper is that of addressing these two aspects in a self-consistent way. First, we introduce suitable measures to quantify the level of combinatoriality and compositionality in a language, and present a framework to estimate these observables in human natural languages. Second, we show that the theoretical predictions of a multi-agents modeling scheme, namely the Blending Game, are in surprisingly good agreement with empirical data. In the Blending Game a population of individuals plays language games aiming at success in communication. It is remarkable that the two sides of duality of patterning emerge simultaneously as a consequence of a pure cultural dynamics in a simulated environment that contains meaningful relations, provided a simple constraint on message transmission fidelity is also considered.

Introduction: In a seminal paper, Charles Hockett BIBREF0 identified duality of patterning as one of the core design features of human language. A language exhibits duality of patterning when it is organized at two distinct levels. At a first level, meaningless forms (typically referred to as phonemes) are combined into meaningful units (henceforth this property will be referred to as combinatoriality). For example, the English forms /k/, /a/, and /t/ are combined in different ways to obtain the three words /kat/, /akt/, and /tak/ (respectively written 'cat', 'act' and 'tack'). Because the individual forms in them are meaningless, these words have no relation in meaning in spite of being made of the same forms. This is a very important property, thanks to which all of the many words of the English lexicon can be obtained by relatively simple combinations of about forty phonemes. If phonemes had individual meaning, this degree of compactness would not be possible. At a second level, meaningful units (typically referred to as morphemes) are composed into larger units, the meaning of which is related to the individual meaning of the composing units (henceforth this property will be referred to as compositionality). For example, the meaning of the word 'boyfriend' is related to the meaning of the words 'boy' and 'friend' which composed it. The compositional level includes syntax as well. For example, the meaning of the sentence 'cats eat fishes' is related to the meaning of the words 'cats', 'eat', and 'fishes'. In this paper, for the sake of simplicity, we focus exclusively on the lexicon level. This has to be considered as a first step towards the comprehension of the emergence of complex structures in languages.

Question: How does the semi-automatic construction process work?
Answer: Automatic transcription of 5000 tokens through sequential neural models trained on the annotated part of the corpus