Hey, gang sorry for the loopback noise. I just had to ask. What tools do you normally use to debug, trace or step functions within the iterate package. I was trying to do a (trace iterate::for previous) & a (trace iterate:for previous) but I keep getting an error about "can't use encapsulation to trace anonymous function" for both iter and for previous. What I was trying to do was see what intern-previous-info and make-save-info was doing to the variables. In the case of the (for (a b) = '(1 2)) ;reported by Kilian Sprotte (for pa previous a) (for pb previous b) (print (list pa pb a b)) -- you must know the ledge of wise and dome to understand your culture of freedom! http://pxpippen.blogspot.com/ http://groups.google.com/group/lispstl Patrick