  Von Wright’s second condition was then to suppose that an interval might be so structured that a given proposition \(p\) and its negation \(\neg p\) are dense in each other throughout the interval. This means that no subinterval, no matter how small, can be found in which just \(p\) holds throughout that subinterval, and no subinterval can be found in which just \(\neg p\) holds throughout the subinterval: every subinterval in which one holds, the other holds as well. From an external point of view admitting instants, we can see that this is a genuine consistent possibility, if for example we think of \(p\) as the proposition that a rational number of seconds has passed, and \(\neg p\) as the proposition that an irrational number of seconds has passed. These are dense in each other on the classical real line regarded as time. Thus, there is no subinterval which is purely \(p\) throughout and no subinterval which is purely \(\neg p\) throughout.