It was found the 120 possible changes of doubles could only be rung by the introduction at some point of "single" changes – that is, changes in which only two bells change position. Only two such singles were required. Historically, it was unclear whether the 5040 (7! = factorial 7 = 7×6×5×4×3×2×1) possible changes of triples required a similar compromise. Although attempts at triples compositions appeared in print as early as 1702, and a peal composed by John Garthon was rung in 1718, it was 1751 before John Holt produced the first satisfactory peal composition.