History of the term

   The current formal definition of the algorithm was given in 30-50-ies of the XX century in the work of Turing, Post, Church (Church's thesis - Turing), N. Wiener, A. Markov.

   The word "algorithm" comes from the scientist Abu Abdullah Muhammad ibn Musa al-Khorezmi. Nearly 825 years later he wrote an essay, which first described the made in India positional decimal number system. Unfortunately, the Arabic original of the book was not kept. Al-Khorezmi formulated the rules of computation in the new system, and probably the first time used the number 0 to indicate the position of the missed record number (its Indian name of the Arabs have translated as the as-sifr or sifr, hence words such as "figure" and the "code" ). Around the same time, the Indian figures began to be applied and other Arab scientists. In the first half of XII century book al-Khorezmi in the Latin translation made inroads into Europe. The interpreter, whose name did not come to us, gave her name Algoritmi de numero Indorum ( "Algorithm account the Indian"). In Arabic as a book called Kitab al-wal Gebre-mukabala ( "A book about addition and subtraction"). Of the original title of the book comes word algebra.

   Thus, we see that the romanized name of Central Asian scholar was rendered in the title of the book, and today no one has a doubt that the word "algorithm" entered into European languages due to this work. However, the question of its meaning a long time aroused fierce controversy. For many centuries the origin of speech given to a variety of explanations.

   Some algorism deduced from the Greek algiros (patient) and arithmos (number). Because of such an explanation is not very clear why the number is "sick". Alternatively, linguists seemed ill people who have the misfortune to deal with calculations? His explanation for the proposed and Courier Brockhaus and Ephron. This algorithm (and, incidentally, before the revolution was used to write algorithm through fitu) is "from the Arabic word Al-Goretm, that is the root". Of course, these explanations can hardly be considered conclusive.

   The above translation of works by al-Khorezmi became the first swallow, and in the next few centuries, many other works dealing with all the same issue - learning the art of using the account numbers. And they are all in the title had the word algorithmic or algorithms.

   About Al-Khorezmi later authors did not know, but since the first translation of the book starts with the words: "Dixit algorizmi: ..." ( "Al-Khorezmi said: ..."), is still linked the word with the name of the individual.