Second, the graph theory term "digraph" (a portmanteau from directed graph) is defined as, "A graph in which each line has a direction associated with it; a finite, non-empty set of elements together with a set of ordered pairs of these elements." The two "digraph" terms were first recorded in 1788 and 1955, respectively. The "OED2" defines two "digraphic" meanings, "Pertaining to or of the nature of a digraph" and "Written in two different characters or alphabets." It gives their earliest examples in 1873 and 1880 (which was used meaning "digraphia"). Isaac Hollister Hall, an American scholar of Oriental studies, described an Eteocypriot language publication as "bilingual (or digraphic, as both inscriptions are in the same language)." Hall's article was antedated by Demetrios Pieridis's 1875 usage of "digraphic" instead of "bilingual" for an inscription written in both the Greek alphabet and Cypriot syllabary. English "digraphic" and "digraphia" were contemporaneous with their corresponding terms in French linguistics. In 1877, Julius Oppert introduced "digraphique" to describe languages written in cuneiform syllabaries. In 1893, Auguste Barth used French "digraphisme" for Cambodian inscriptions written in Khmer script and Brāhmī script. In 1971, Robèrt Lafont coined "digraphie" regarding the sociolinguistics of French and Occitan. Although the word "digraphia" is new, the practice is ancient. Darius the Great's (c. 522-486 BCE) Behistun Inscription was written in three cuneiform scripts for Old Persian, Elamite, and Babylonian. Four authors independently neologized English "digraphia" from "diglossia". The Songhay linguist Petr Zima (1974) first used "digraphia" to describe the Hausa language having two writing systems, Boko (Latin script) and Ajami script (Arabic script). Zima differentiated these paired situations. Usage of "diorthographia" is unusual. Compare dysgraphia meaning "a language disorder that affects a person's ability to write" and dysorthographia "a synonym for dyslexia". The anthropologist James R. Jaquith (1976), who studied unconventional spelling in advertising, used "digraphia" to describe the practice of writing brand names in all caps (e.g., ARRID).