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
Nested word a matching relation of length formula_1. Nested words over the alphabet formula_10 can be encoded into "ordinary" words over the "tagged alphabet" formula_11, in which each symbol "a" from Σ has three tagged counterparts: the symbol ⟨a for encoding a call position in a nested word labelled with "a", the symbol a⟩ for encoding a return position labelled with "a", and finally the symbol a itself for representing an internal position labelled with "a". More precisely, let "φ" be the function mapping nested words over Σ to words over formula_12 such that each nested word (formula_13,↝) is mapped to the