+ (if (and (zerop base) (floatp power))
+ (error 'arguments-out-of-domain-error
+ :operands (list base power)
+ :operation 'expt
+ :references (list '(:ansi-cl :function expt)))
+ (let ((result (1+ (* base power))))
+ (if (and (floatp result) (float-nan-p result))
+ (float 1 result)
+ result)))