math functions for Clojure

 math.numeric-tower provides math functions that deal intelligently with the
 various types in Clojure's numeric tower, as well as math functions
 commonly found in Scheme implementations:
 .
   * (expt x y) - x to the yth power
   * (abs n) - absolute value of n
   * (gcd m n) - greatest common divisor of m and n
   * (lcm m n) - least common multiple of m and n
   * (floor x) - round down
   * (ceil x) - round up
   * (round x) - round to nearest
   * (sqrt x) - square root, exact if possible
   * (exact-integer-sqrt k) returns floor of square root and the "remainder"