Revise the description of when functions retrieved from class instances

are and are not turned into bound methods; some confusion was noted by
Andrew Dalke.

In particular, it has to be noted that functions located on the class
instance are not turned into any sort of method, only those which are
found via the underlying class.

Doc/ref/ref3.tex

@@ -438,11 +438,12 @@ base class of the class of which \member{im_self} is an instance);
 
 User-defined method objects are created in two ways: when getting an
 attribute of a class that is a user-defined function object, or when
-getting an attributes of a class instance that is a user-defined
-function object.  In the former case (class attribute), the
-\member{im_self} attribute is \code{None}, and the method object is said
-to be unbound; in the latter case (instance attribute), \method{im_self}
-is the instance, and the method object is said to be bound.  For
+getting an attribute of a class instance that is a user-defined
+function object defined by the class of the instance.  In the former
+case (class attribute), the \member{im_self} attribute is \code{None},
+and the method object is said to be unbound; in the latter case
+(instance attribute), \method{im_self} is the instance, and the method
+object is said to be bound.  For
 instance, when \class{C} is a class which contains a definition for a
 function \method{f()}, \code{C.f} does not yield the function object
 \code{f}; rather, it yields an unbound method object \code{m} where
@@ -452,9 +453,7 @@ instance, \code{x.f} yields a bound method object \code{m} where
 \code{m.im_class} is \code{C}, \code{m.im_func} is \method{f()}, and
 \code{m.im_self} is \code{x}.
 \withsubitem{(method attribute)}{
-  \ttindex{im_class}
-  \ttindex{im_func}
-  \ttindex{im_self}}
+  \ttindex{im_class}\ttindex{im_func}\ttindex{im_self}}
 
 When an unbound user-defined method object is called, the underlying
 function (\member{im_func}) is called, with the restriction that the
@@ -474,7 +473,10 @@ the class or instance.  In some cases, a fruitful optimization is to
 assign the attribute to a local variable and call that local variable.
 Also notice that this transformation only happens for user-defined
 functions; other callable objects (and all non-callable objects) are
-retrieved without transformation.
+retrieved without transformation.  It is also important to note that
+user-defined functions which are attributes of a class instance are
+not converted to bound methods; this \emph{only} happens when the
+function is an attribute of the class.
 
 \item[Built-in functions]
 A built-in function object is a wrapper around a \C{} function.  Examples