... necessary; in this case, it is precisely the end point of the building event that coincides with the beginning of the event of the house being new. In a system using Allen's primitives, the ... tion that the cake is warm while John is frosting it, the time span during which the cake is warm must include the time 3:00; however, the starting and ending points of the cake-frosting event ... house." The building event can be thought of as beginning before the event of the house's being new. At the start of the building event, there is no house, nor, obviously, is there is any...