Lojban is a constructed language based on predicate logic. It was created by the Logical Language Group between 1987 and 1997. Lojban is designed to be spoken by humans, but is also theoretically computer-speakable. The majority of its grammar is borrowed from the first "logical language," Loglan, and some of its features come from Láadan. Most of Lojban's root words derive from the six most widely spoken natural languages, Arabic, Chinese, English, Hindi, Russian, and Spanish. The characteristic regularity, unambiguity, and versatility of Lojban grammar owes much to scientific linguistics and computer programming—resources that were unavailable to the designers of earlier languages. An advantage of Lojban as a speakable language over other languages was summarized as follows: "Lojban moves beyond the restrictions of European grammar. It overtly incorporates linguistic universals, building in what is needed to support the expressivity of the whole variety of natural languages, including non-European ones."