Exactly! The officer needs to know how many men are available (a platoon of one wouldn't perform well either). He could have asked, "How many are available?" But he didn't (in this example). Presumably he can see there's no one there, so he effectively asked, "Is this everyone in the platoon?" The correct answer at that point is "Yes", at which point he knows what he has to work with (even if it's zero). To answer No at this point would imply that there are others who are not present, which isn't the case. If we were to write that in code, it would be Platoon.AreAllPresent(), and the result would be True as long as no members of the Platoon are absent (even if there are no members of the Platoon).