Iota

Iota (uppercase Ι, lowercase ι; Template:Lang-el [jɒta] Yota) is the ninth letter of the Greek alphabet. In the system of Greek numerals it has a value of 10. It was derived from the Phoenician letter Yodh (). Letters that arose from Iota include the Roman I and J.

Iota represents IPA: [/i/]. In ancient Greek it occurred in both long [i:] and short [i] versions, but this distinction has been lost in Modern Greek.

Iota participated as the second element in falling diphthongs, with both long and short vowels as the first element. Where the first element was long, the iota was lost in pronunciation at an early date, and was written in polytonic orthography as iota subscript in other words as a very small ι under the main vowel, for instance Template:Polytonic

Common English phrase

The word is used in a common English phrase, 'not one iota of difference', to signify a meaningless distinction (lit. "not even a small difference"). The phrase derives from the introduction to the Antithesis of the Law in the Gospel of Matthew (a jot or a tittle), and became common in the theological debate which arose around the time of the First Council of Nicaea, regarding the nature of the Holy Trinity. The argument centered on which of two alternative Greek words, differing only in a single 'iota' letter, should be used in describing Jesus' relationship to the Holy Trinity. One word, 'homoousios', would mean that Jesus was of the same substance as God the Father, and the other 'homoiousios', would mean that Jesus was of similar substance.

Symbol

• The Iota symbol is used to generate a vector of consecutive integers in the APL programming language.
• The lowercase Iota symbol is sometimes used to write the imaginary unit but more often Roman i or j are used.
• In logic, the lowercase iota denotes the definite descriptor.