* src/fns.c (Feql, Fequal): Improve floating-point doc.

diff --git a/src/fns.c b/src/fns.c
index 7d120a90f78cea2b4888ed9faebf5d914f7b523c..e7424c34718405ebb6319cf86dd5d60c616fc243 100644 (file)
--- a/src/fns.c
+++ b/src/fns.c
@@ -2193,8 +2193,10 @@ The PLIST is modified by side effects.  */)
 }
 \f
 DEFUN ("eql", Feql, Seql, 2, 2, 0,
-       doc: /* Return t if the two args are the same Lisp object.
-Floating-point numbers of equal value are `eql', but they may not be `eq'.  */)
+       doc: /* Return t if the two args are `eq' or are indistinguishable numbers.
+Floating-point values with the same sign, exponent and fraction are `eql'.
+This differs from numeric comparison: (eql 0.0 -0.0) returns nil and
+\(eql 0.0e+NaN 0.0e+NaN) returns t, whereas `=' does the opposite.  */)
   (Lisp_Object obj1, Lisp_Object obj2)
 {
   if (FLOATP (obj1))
@@ -2208,8 +2210,8 @@ DEFUN ("equal", Fequal, Sequal, 2, 2, 0,
 They must have the same data type.
 Conses are compared by comparing the cars and the cdrs.
 Vectors and strings are compared element by element.
-Numbers are compared by value, but integers cannot equal floats.
- (Use `=' if you want integers and floats to be able to be equal.)
+Numbers are compared via `eql', so integers do not equal floats.
+\(Use `=' if you want integers and floats to be able to be equal.)
 Symbols must match exactly.  */)
   (Lisp_Object o1, Lisp_Object o2)
 {