--- a/LimitedPrecisionReal.st	Sat Aug 31 16:13:18 2019 +0200
+++ b/LimitedPrecisionReal.st	Sat Aug 31 16:13:30 2019 +0200
@@ -1580,6 +1580,8 @@
 !LimitedPrecisionReal methodsFor:'testing'!
 
 isFinite
+    "return true, if the receiver is a finite float (not NaN and not +/-INF)"
+
    ^ self subclassResponsibility
 
     "Created: / 7.1.1998 / 12:02:06 / stefan"
@@ -1596,9 +1598,9 @@
 !
 
 isInfinite
-    "return true, if the receiver is an infinite float (Inf).
+    "return true, if the receiver is an infinite float (+Inf or -Inf).
      These are not created by ST/X float operations (they raise an exception);
-     however, inline C-code could produce them ..."
+     however, inline C-code could produce them."
 
     ^ (self isFinite or:[self isNaN]) not.
 
@@ -1619,6 +1621,10 @@
 !
 
 isNaN
+    "return true, if the receiver is an invalid float (NaN - not a number).
+     These are not created by ST/X float operations (they raise an exception);
+     however, inline C-code could produce them."
+
    ^ self subclassResponsibility
 
     "Modified: 12.2.1997 / 16:45:27 / cg"