Palindrome

A palindrome is a word, number, phrase, or other sequence of symbols that reads the same backwards as forwards, such as madam or racecar, the date "22/02/2022" and the sentence: "A man, a plan, a canal – Panama".

[10] Byzantine baptismal fonts were often inscribed with the 4th-century Greek palindrome, ΝΙΨΟΝ ΑΝΟΜΗΜΑΤΑ (or ΑΝΟΜΗΜΑ) ΜΗ ΜΟΝΑΝ ΟΨΙΝ ("Nipson anomēmata mē monan opsin") 'Wash [your] sin(s), not only [your] face', attributed to Gregory of Nazianzus;[11] most notably in the basilica of Hagia Sophia in Constantinople.

The inscription is found on fonts in many churches in Western Europe: Orléans (St. Menin's Abbey); Dulwich College; Nottingham (St. Mary's); Worlingworth; Harlow; Knapton; London (St Martin, Ludgate); and Hadleigh (Suffolk).

[12] A 12th-century palindrome with the same square property is the Hebrew palindrome, פרשנו רעבתן שבדבש נתבער ונשרף perashnu: ra`avtan shebad'vash nitba`er venisraf 'We explained the glutton who is in the honey was burned and incinerated', credited in 1924 to the medieval Jewish philosopher Abraham ibn Ezra,[13][unreliable fringe source?]

The palindromic Latin riddle "In girum imus nocte et consumimur igni" 'we go in a circle at night and are consumed by fire' describes the behavior of moths.

This is generally considered the first English-language palindrome sentence and was long reputed, notably by the grammarian James "Hermes" Harris, to be the only one, despite many efforts to find others.

[16][17] (Taylor had also composed two other, "rather indifferent", palindromic lines of poetry: "Deer Madam, Reed", "Deem if I meed".

The longest common ones are rotator, deified, racecar, and reviver; longer examples such as redivider, kinnikinnik, and tattarrattat are orders of magnitude rarer.

[25] Palindromes often consist of a sentence or phrase, e.g., "A man, a plan, a canal, Panama", "Mr. Owl ate my metal worm", "Do geese see God?

Nisio Isin is a Japanese novelist and manga writer, whose pseudonym (西尾 維新, Nishio Ishin) is a palindrome when romanized using the Kunrei-shiki or the Nihon-shiki systems, and is often written as NisiOisiN to emphasize this.

Some people have changed their name in order to make it palindromic (including as the actor Robert Trebor and rock-vocalist Ola Salo), while others were given a palindromic name at birth (such as the philologist Revilo P. Oliver, the flamenco dancer Sara Baras, the runner Anuța Cătună, the creator of the Eden Project Tim Smit, and the Mexican racing driver Noel León).

Five of the fictional Pokémon species have palindromic names in English (Eevee, Girafarig, Farigiraf, Ho-Oh, and Alomomola), as does the region Alola.

[30] In the French language, there is the phrase une Slave valse nue ("a Slavic woman waltzes naked"), phonemically /yn slav vals ny/.

[31] John Oswald discussed his experience of phonetic palindromes while working on audio tape versions of the cut-up technique using recorded readings by William S.

Michaelsen (Ove Ofteness) include "crew work"/"work crew", "dry yard", "easy", "Funny enough", "Let Bob tell", "new moon", "selfless", "Sorry, Ross", "Talk, Scott", "to boot", "top spot" (also an orthographic palindrome), "Y'all lie", "You're caught.

[34] The longest single-word palindrome in the Oxford English Dictionary is the 12-letter onomatopoeic word tattarrattat, coined by James Joyce in Ulysses (1922) for a knock on the door.

The 9-letter word Rotavator, a trademarked name for an agricultural machine, is listed in dictionaries as being the longest single-word palindrome.

[12] English palindrome sentences of notable length include mathematician Peter Hilton's "Doc, note: I dissent.

I diet on cod",[38] and Scottish poet Alastair Reid's "T. Eliot, top bard, notes putrid tang emanating, is sad; I'd assign it a name: gnat dirt upset on drab pot toilet.

"[39] In English, two palindromic novels have been published: Satire: Veritas by David Stephens (1980, 58,795 letters), and Dr Awkward & Olson in Oslo by Lawrence Levine (1986, 31,954 words).

The interlude from Alban Berg's opera Lulu is a palindrome,[43] as are sections and pieces, in arch form, by many other composers, including James Tenney, and most famously Béla Bartók.

George Crumb also used musical palindrome to text paint the Federico García Lorca poem "¿Por qué nací?

For example, Karlheinz Stockhausen's composition Mixtur, originally written in 1964, consists of twenty sections, called "moments", which may be permuted in several different ways, including retrograde presentation, and two versions may be made in a single program.

When the composer revised the work in 2003, he prescribed such a palindromic performance, with the twenty moments first played in a "forwards" version, and then "backwards".

[46] By contrast, Karel Goeyvaerts's 1953 electronic composition, Nummer 5 (met zuivere tonen) is an exact palindrome: not only does each event in the second half of the piece occur according to an axis of symmetry at the centre of the work, but each event itself is reversed, so that the note attacks in the first half become note decays in the second, and vice versa.

A large-scale musical palindrome covering more than one movement is called "chiastic", referring to the cross-shaped Greek letter "χ" (pronounced /ˈkaɪ/.)

Other examples are found in Bach's cantata BWV 4, Christ lag in Todes Banden, Handel's Messiah and Fauré's Requiem.

The result is somewhat like two speakers simultaneously reading the Sator Square from opposite sides, except that it is typically in two-part polyphony rather than in unison.

Palindromic motifs are made by the order of the nucleotides that specify the complex chemicals (proteins) that, as a result of those genetic instructions, the cell is to produce.

In addition, the set of palindromes may not be reliably tested by a deterministic pushdown automaton which also means that they are not LR(k)-parsable or LL(k)-parsable.