expt

[procedure] expt z1 z2

R5RS, R6RS: Returns z1 raised to the power of z2.

R6RS defines these boundary cases:

  (expt 0.0 0.0)  => 1.0
  (expt 0.0 z2)   => 0.0 if (real-part z2) is positive
                  => unspecified otherwise

See also log.