Derailleur gears operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets. For more information about the choice of particular gear ratios and sprocket sizes, see Bicycle gearing. "Derailleur" is a French word, spelled "dérailleur" in French, derived from the derailment of a train from its tracks. Its first recorded use was 1930. At least one notable bicycle industry author has attempted to promote the anglicized spelling of "derailer". As of 2013, however, neither Merriam-Webster nor the Oxford English Dictionary has an entry for "derailer". Various derailleur systems were
Word RAM RAM model, and was the original motivation for the model. Dan Willard used y-fast tries to solve this in formula_6 time. Michael Fredman and Willard also solved the problem using fusion trees in formula_7 time. Word RAM In theoretical computer science, the word RAM (word random access machine) model is a model of computation that is a random access machine able to do bitwise operations on a single word of bits. The model was created by Michael Fredman and Dan Willard in 1990 to simulate programming languages like C. The word RAM model is an abstract machine similar to a