### The Man

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According to Wikipedia:

Levi ben Gershon, better known by his Latinised name as Gersonides or
the abbreviation of first letters as RaLBaG ... (1288–1344),
philosopher, Talmudist, mathematician, astronomer/astrologer.
He was born at Bagnols in Languedoc, France. According to Abraham Zacuto and others,
he was the son of Gerson ben Solomon Catalan.

...

Gersonides wrote Maaseh Hoshev in 1321 dealing with arithmetical operations including
extraction of square and cube roots, various algebraic identities, certain sums including
sums of consecutive integers, squares, and cubes, binomial coefficients, and simple
combinatorial identities. The work is notable for its early use of proof by mathematical
induction, and pioneering work in combinatorics. The title Maaseh Hoshev literally
means a Work of Calculation, but it is also a pun on a biblical phrase meaning "clever work"[or "cunning work"].
Additional biographical information and references can be found at The MacTutor History of Mathematics archive
Levi Ben Gershon page

Levi ben Gershon, better known by his Latinised name as Gersonides or the abbreviation of first letters as RaLBaG ... (1288–1344), philosopher, Talmudist, mathematician, astronomer/astrologer. He was born at Bagnols in Languedoc, France. According to Abraham Zacuto and others, he was the son of Gerson ben Solomon Catalan.

...

Gersonides wrote Maaseh Hoshev in 1321 dealing with arithmetical operations including extraction of square and cube roots, various algebraic identities, certain sums including sums of consecutive integers, squares, and cubes, binomial coefficients, and simple combinatorial identities. The work is notable for its early use of proof by mathematical induction, and pioneering work in combinatorics. The title Maaseh Hoshev literally means a Work of Calculation, but it is also a pun on a biblical phrase meaning "clever work"[or "cunning work"]. Additional biographical information and references can be found at The MacTutor History of Mathematics archive Levi Ben Gershon page