Go-go dancing 1960s-era clubgoers wore miniskirts and knee-high, high-heeled boots, which eventually came to be called go-go boots. Night club promoters in the mid‑1960s then conceived the idea of hiring women dressed in these outfits to entertain patrons. The term "go-go" derives from the phrase "go-go-go" for a high-energy person, and was influenced by the French expression "à gogo", meaning "in abundance, galore", which is in turn derived from the ancient French word "la gogue" for "joy, happiness". On 19 June 1964, Carol Doda began go-go dancing topless at the Condor Club on Broadway and Columbus in the North Beach neighborhood of
Lyndon word over a field of characteristic 0 can be viewed as a polynomial algebra over the Lyndon words. More precisely, let "A" be an alphabet, let "k" be a field of characteristic 0 (or, more general, a commutative ℚ-algebra), and let "R" be the free noncommutative "k"-algebra . The words over "A" can then be identified with the "noncommutative monomials" (i.e., products of the "x") in "R"; namely, we identify a word ("a","a"...,"a") with the monomial "x""x"..."x". Thus, the words over "A" form a "k"-vector space basis of "R". Then, a "shuffle product" is defined on "R"; this is a "k"-bilinear,