--- Vladimir Nesov <[EMAIL PROTECTED]> wrote: > On Sat, May 10, 2008 at 2:09 AM, Matt Mahoney <[EMAIL PROTECTED]> > wrote: > > > > --- Vladimir Nesov <[EMAIL PROTECTED]> wrote: > >> > >> (I assume you mean something like P((P,y))=P(y)). > >> > >> If P(s)=0 (one answer to all questions), then P((P,y))=0 and P(y)=0 > >> for all y. > > > > You're right. But we wouldn't say that the trivial language P = > {0,1}* > > "understands" anything. That is a problem with my formal definition > > of "understanding". > > > > Then make a definition that fits your claim. As currently stated, it > looks erroneous to me, and I can't see how it's possible to fix that > without explicating your assertion mathematically.
OK, let me make more clear the distinction between running a program and simulating it. Say that a program P simulates a program Q if for all y, P((Q,y)) = "the output is "+Q(y) where + means string concatenation. In other words, given Q and y, P prints not Q(y) but a statement describing what the output Q(y) would be. Then I claim there is no finite state machine P that can simulate itself (including the trivial case). P needs as many states as Q to simulate it, plus additional states to print "the output is ". I also claim that "P understands Q" can be reasonably interpreted as "P can simulate Q", but I can't prove it :-) -- Matt Mahoney, [EMAIL PROTECTED] ------------------------------------------- agi Archives: http://www.listbox.com/member/archive/303/=now RSS Feed: http://www.listbox.com/member/archive/rss/303/ Modify Your Subscription: http://www.listbox.com/member/?member_id=8660244&id_secret=101455710-f059c4 Powered by Listbox: http://www.listbox.com