Comment 2 for bug 793771

Fixed:

commit 26627f70af3ede3610e4092175965e0250456a4d
Author: Nikodemus Siivola <email address hidden>
Date: Tue Jun 7 14:14:21 2011 +0300

    more conservative bounds in FP interval arithmetic

     Make BOUND-BINOP return closed intervals when floating
     point rounding can cause an open bound to close.

     Consider:

      ;; Can return zero.
      (defun fii (x)
        (declare (type (single-float (0.0)) x))
        (/ x 2.0))

      ;; Can return 2.0.
      (defun fii (x y)
        (declare (type (single-float 2.0) x)
                 (type (single-float (0.0)) y))
        (+ x y))