anchor.diff:      (when (float-infinity-p d)
         (setf u (/ 0.0f0 0.0f0)))
   
  -    u))
  +    (if (floatp d)
  +        (float u d)
  +        u)))
   
   (defun tan (radians)
     (etypecase radians
  
positive.code:             tt))))
  
  (defun atan2 (y x)
    (cond ((> x 0) (atan (/ y x)))
          ((and (>= y 0) (< x 0))
           (+ (atan (/ y x)) pi))
          ((and (< y 0) (< x 0))
           (- (atan (/ y x)) pi))
          ((and (> y 0) (zerop x))
           (/ pi 2))
          ((and (< y 0) (zerop x))
           (- (/ pi 2)))
          (t 0)))
  
  (defun two-arg-gcd (a b)
    (check-type a integer)
  
negative.code:                 (* (cos real) (sinh imag)))))
      (double-float
       (sin-double-float x))
      (short-float
       (float (sin-single-float (float x 0.0f0)) #.(xshort-float 0.0s0)))
      (real
       (sin-single-float (float x 0.0f0)))))
  
  