environment; if the variable is not specified in there, it looks in
the symbol's value cell, where the dynamic value is stored.
- (Internally, the lexical environment is an alist of symbol-value
-pairs, with the final element in the alist being the symbol @code{t}
-rather than a cons cell. Such an alist can be passed as the second
-argument to the @code{eval} function, in order to specify a lexical
-environment in which to evaluate a form. @xref{Eval}. Most Emacs
-Lisp programs, however, should not interact directly with lexical
-environments in this way; only specialized programs like debuggers.)
+ (Internally, the lexical environment is a list whose members are
+usually cons cells that are symbol-value pairs, but some of its
+members can be symbols rather than cons cells. A symbol in the list
+means the lexical environment declared that symbol's variable as
+locally considered to be dynamically bound. This list can be passed
+as the second argument to the @code{eval} function, in order to
+specify a lexical environment in which to evaluate a form.
+@xref{Eval}. Most Emacs Lisp programs, however, should not interact
+directly with lexical environments in this way; only specialized
+programs like debuggers.)
@cindex closures, example of using
Lexical bindings have indefinite extent. Even after a binding