1.   Chaotic behaviour is important, for example, with regard to the weather.

2.   These are the terms that are considered to induce chaotic behaviour in these cosmological models.

3.   Chaotic behaviour can arise only when the governing equations are non-linear.

4.   Because some of the systems that exhibit chaotic behaviour are so simple, it seems strange that the realization that they can behave in this way is only recent.

5.   An important aspect of such chaotic behaviour is sensitivity to initial conditions.