# Abacus

The abacus, also called a counting frame, is a calculating tool which has been used since ancient times. It was used in the ancient Near East, Europe, China, and Russia, centuries before the adoption of the Hindu-Arabic numeral system. The exact origin of the abacus has not yet emerged. It consists of rows of movable beads, or similar objects, strung on a wire. They represent digits. One of the two numbers is set up, and the beads are manipulated to perform an operation such as addition, or even a square or cubic root.
The Abbadid dynasty or Abbadids was an Arab Muslim dynasty which arose in al-Andalus on the downfall of the Caliphate of Cordoba (756–1031). After the collapse, there were multiple small Muslim states called taifas, each ruled by a different family or
Pietro d'Abano
Pietro d'Abano, also known as Petrus de Apono, Petrus Aponensis or Peter of Abano, was an Italian philosopher, astrologer, and professor of medicine in Padua. He was born in the Italian town from which he takes his name, now Abano Terme. He gained fame by
Abettor
Abettor, is a legal term implying one who instigates, encourages or assists another to commit an offence
Prosthaphaeresis
Prosthaphaeresis was an algorithm used in the late 16th century and early 17th century for approximate multiplication and division using formulas from trigonometry. For the 25 years preceding the invention of the logarithm in 1614, it was the only known
Co-NP-complete
In complexity theory, computational problems that are co-NP-complete are those that are the hardest problems in co-NP, in the sense that any problem in co-NP can be reformulated as a special case of any co-NP-complete problem with only polynomial overhead
Soroban
The soroban is an abacus developed in Japan. It is derived from the ancient Chinese suanpan, imported to Japan in the 14th century. Like the suanpan, the soroban is still used today, despite the proliferation of practical and affordable pocket electronic
Firmin Abauzit
Firmin Abauzit was a French scholar who worked on physics, theology and philosophy, and served as librarian in Geneva during his final 40 years. Abauzit is also notable for proofreading or correcting the writings of Isaac Newton and other scholars
Abbess
In Catholicism, an abbess is the female superior of a community of nuns, which is often an abbey
M-derived filter
m-derived filters or m-type filters are a type of electronic filter designed using the image method. They were invented by Otto Zobel in the early 1920s. This filter type was originally intended for use with telephone multiplexing and was an improvement
France Bleu Pays de Savoie
France Bleu Pays de Savoie, sometimes referred to as France Bleu Savoie, is a generalist radio station based in Chambéry. The radio station serves the departments of Savoie and Haute-Savoie, though it can also be received as far as Geneva, Lyon, and in