Sample of using DependencyObsevation. letting the viewmodel know the dependencies of a property (calling RaisePropertyChanged when those change)

DependencyObservation.cs

public string FullName
{
    get
    {
        using (var obs = DependencyObservation.Of(this, @this => @this.FullName))
        {
            return obs.Follow(@this => @this.FirstName) + obs.Follow(@this => @this.LastName);
        }
    }
}