Extension Pattern: By definition an extension occurs in an impulsive wave, where waves 1, 3 or 5 can be extended, being much longer than the other waves. It is quite common that one of these waves will extend, which is normally the third wave. The two other waves then tend to equal each other. In our pattern definitions we call it an Extension1 if the first wave extends, an Extension3 if the 3rd wave extends and an Extension5 if the 5th wave extends.