Inspired by a comment from Michael Heerdegen (Bug#40671#114).
* doc/lispref/objects.texi (Constants and Mutability): Tweak further.
call @code{(make-string 3 ?a)} yields a mutable string that can be
changed via later calls to @code{aset}.
- A mutable object can become constant if it is passed to the
-@code{eval} function, because a program should not modify an object
+ A mutable object can become constant if it is part of an expression
+that is evaluated, because a program should not modify an object
that is being evaluated. The reverse does not occur: constant objects
should stay constant.