2014-11-17: justification: note the requirement for the dot.

justification: note the requirement for the dot.

diff --git a/docs/srfi.org b/docs/srfi.org
--- a/docs/srfi.org
+++ b/docs/srfi.org
@@ -369,6 +369,8 @@ See also http://draketo.de/light/english
 
 ** . (the dot)
 
+To represent general code trees, we have to be able to represent continuation of the arguments of a function with an intermediate call to another (or the same) function.
+
 The dot at the beginning of the line as marker of the continuation of a variable list is a generalization of using the dot as identity function - which is an implementation detail in many lisps.
 
 #+BEGIN_QUOTE