Fans of Tai Chi ?

I have decided to try and walk early every morning (bar rain) in The Botanic Gardens.
The early mornings are very busy with dog walkers, joggers, runners, boot camp groups, walkers, sweepers and many many people practising Tai chi.
There must be many different types of Tai Chi but they are all interesting to watch and include people of all ages, from young to the very old.
Today I counted 15 different groups
This particular group were using fans, and although a small group, they were obviously well practised as they moved completely in unison.