Any system of letters or symbols used for writing, which represents speech sounds or language; implicitly entails phoneme, allomorph, syllable, homonym / homograph / homophone, heteronym, doublet, orthoepy, paragoge, apheresis, prothesis, syncope, metathesis, sandhi, haplology, spoonerism, anagram, acrostic, abecedari. See digraph, ligature, logo, diacritic, morpheme, syllabary, elision, punctuation, syntax, vowel, parse, pidgin, type, typology, font, rune, orthography, oxymoron, neologism, dictionary, semantics, semiotics, lexigram, pictography, ideogram, language, rhetorical forms. The earliest dated written material is c4236BC from Egypt. Sumerian pictography ca3500BC became Mesopotamian cuneiform ("wedge shaped") writing, as used by the ancient Akkadians, Assyrians, Babylonians, Persians, and others. The simple Greek alphabet (16 letters by Cadmus, and 4 letters by Palamedes) was introduced from Phoenicia. Alphabets independently invented elsewhere, as Egyptian hieroglyphics ca3,000BC, Minoan Linear-A / Mycenean Linear-B ca1200BC, Indus Valley script (at Mohenjo-Daro and Harappa) ca3,000-2,400BC, Chinese (ideogram) seal script ca1,500BC, Mayan script caAD50, Ogham (Irish Ogam/Ogum) alphabetic script caAD400-1000, Irish Gaelic caAD1175, Aztec Kipu script caAD1400.