Good question indeed. I never really thought about that one. I guess it might be best to close both, though, because in some rare occasions or program, the slow down continues during the entire duration of the program afterward. In my case, in Illusiat 13, after you unlock the Holy Sanctuary with the 4 keys the entire game slowed down by about half the normal speed all of a suddent. Closing the For() loop parhentesises in there fixed the problem. The slow down, otherwise, would only end when exiting the game.