Variable-Precision Exponentiation A previous paper presented an efficient algorithm, called the Recomputation Algorithm, for evaluating a rational expression to within any desired tolerance on a computer which performs variable-precision arithmetic operations. The Recomputation Algorithm can be applied to expressions involving any variable-precision operations having O(10^(-p) + SUM{|Ei|}) error bounds, where p denotes the operation's precision and Ei denotes the error in the operation's ith argument. This paper presents an efficient variable-precision exponential operation with an error bound of the above order. Other operations such as log, sin, and cos, which have simple series expansions, can be handled similarly. CACM January, 1973 Richman, P. L. variable-precision, exponential function, error analysis, interval arithmetic 5.11 CA730106 JB January 24, 1978 4:32 PM 2555 4 2555 2605 4 2555 2286 5 2555 2555 5 2555 2555 5 2555 2555 5 2555