---------- Forwarded message ---------- From: Lev Broido Date: Mon, Oct 31, 2011 at 2:31 PM Subject: Stuck in debug of loop detection To: beginners@haskell.org, haskell-cafe@haskell.org Hi I am playing around with building graph using 'tying the knote' technique , according to rule a is child of b iff predicate a b == true Additional step is to detect loops in graph to enable it's print . Then I am using graph traversal to detect loops prior to calling show . For now I am stuck debugging loop detection . I am using 'trace' for a first time and I am not sure I am fully understanding it's behavior In additional I tried to make all calculations strict for debug . Can you please provide tips / review code . My code is at http://pastebin.com/5RvQ42z2 Thanks, Lev