You should consider asking your professor and TAs for help! <blockquote type="cite">On Aug 7, 2009 11:46 AM, "emre berat nebioğlu" <<a href="mailto:beratn@gmail.com">beratn@gmail.com</a>> wrote: Hey i read plai chapter 6 page 46.We define a new datatype FAE-Value.There i,s a new concept "definition-time" repository. Sentence said "we define new datatype that attaches definition time-repository to every function value" i cannot understand this concept.What is it ? Can someone explain thanks _________________________________________________ For list-related administrative tasks: <a href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme" target="_blank">http://list.cs.brown.edu/mailman/listinfo/plt-scheme</a> </blockquote>