Drew Adams wrote: Does anyone know that these are not equivalent:
(equal 0.0e+NaN) <=?=> (and (numberp x) (/= x x)) That is, are there any objects equal to 0.0e+NaN that are not NaN? They are equivalent. internal_equal contains: case Lisp_Float: { double d1, d2; d1 = extract_float (o1); d2 = extract_float (o2); /* If d is a NaN, then d != d. Two NaNs should be `equal' even though they are not =. */ return d1 == d2 || (d1 != d1 && d2 != d2); } Yes, for testing a numberp to see if it is not NaN. However, I am testing an arbitrary object. For that, (and (numberp x) (/= x x)) works and (equal x 0.0e+Nan) works. Yes. Sincerely, Luc. _______________________________________________ Emacs-devel mailing list Emacs-devel@gnu.org http://lists.gnu.org/mailman/listinfo/emacs-devel