Guards and constant enclosures

During the past weeks Jan has been working towards an implementation of a hybrid ODE solver for problems with interval initial conditions. The solver is based on using functions as the base numeric type. To get a working prototype as quickly as possible Jan has been implementing the first version using constant functions but has noticed that they do not force him to address some complexities that only arise when dealing with non-constant function representations. One example is the problem of determining when a guard holds for the solution over a given interval. For a constant function it is not possible to separate cases when the guard holds everywhere from those when it holds only at some points in the interval. Jan is currently finishing the implementation of event detection, after which he will start implementing a simple version of non-constant function enclosures that will make it possible to test the solver properly.